Mailfromd NEWS -- history of user-visible changes. 2025-12-11
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Please send Mailfromd bug reports to <bug-mailfromd@gnu.org.ua>

version 9.1, 2025-12-11

* Arguments to prog action

Action hook is passed source location where the action was called.
Thus, its arguments are:

  1. Identifier of the action.
  2. SMTP code of the reply.
  3. Extended reply code.
  4. Textual message passed to the action.
  5. File name of the source location where the action was called.
  6. Line number of source location where the action was called.

* New debugging functions

  string stack_trace_format(string fmt)
  string stack_trace_top(string fmt)

These functions format the stack trace at the current point according
to the format string fmt.  stack_trace_format applies fmt to each
frame, and returns the concatenated string. stack_trace_top applies
fmt to the top-level frame.

* Fix the clamav function

The function used a deprecated interface that was removed in clamav
version 0.104.

* Callout: return the "less critical" answer if no MX gives a definite one.

For example, assume three MXs queried during a callout session
returned three different results: mf_timeout, mf_temp_failure, and
mf_failure.  Then, the result of callout_mx will be mf_temp_failure.

* Bugfixes

** Accept DNS replies containing forbidden characters

** $i macro is available for use in all handlers

This fixes a bug introduced in version 9.0.


Version 9.0, 2024-01-05

* Compatibility .mf suffix not supported any more

* Begin and end handlers must be defined using prog keyword

* Module and include search paths

Since version 8.15, if a module was not found in module search path,
the search was retried using include search path.  This is no longer
the case: the two paths serve different purposes and don't interact
in any way.  MFL modules are searched in module search path only.

* Use of Sendmail macros in run mode

Sendmail macros can be defined in run mode by placing assignments
macro=value before the script file name, e.g.:

  mailfromd --run i=123 client_addr=::1 test.mfl foo bar baz

This example defines Sendmail macro "i" to "123" and "client_addr" to
"::1".  The words "foo", "bar", and "baz" will be passed to the
main function as positional parameters.

* Full IPv6 support

This causes changes in the following MFL functions (see also "New functions",
below):

** dns_query

 number dns_query (number TYPE, string DOMAIN; number SORT, number RESOLVE)

The semantics and possible values of the RESOLVE argument have
changed.  It used to be a boolean value.  Now its allowed values (as
defined in status.mfl module) are:

     'RESOLVE_NONE'
          Don't resolve hostnames to IP addresses.  This is the default.

     'RESOLVE_DFL'
          Resolve hostnames to IP addresses according to the address
          family of the SMTP session.  That is, use 'A' records if the
          client connected using the INET family (i.e.  connected to the
          IPv4 address), and use 'AAAA' records if the client connected
          to the IPv6 address.

     'RESOLVE_IP4'
          Resolve hostnames to IPv4 addresses ('A' records).

     'RESOLVE_IP6'
          Resolve hostnames to IPv6 addresses ('AAAA' records).

Values of these constants has been selected so that any existing
code using 0/1 as the value of this argument will work without
changes.

** primitive_resolve and resolve functions

 string primitive_resolve (string HOST; string DOMAIN, number FAMILY)
 string resolve (string HOST; string DOMAIN, number FAMILY)

The use of DOMAIN argument is deprecated.

By default the function selects the type of RR set to search for
using the address family of the SMTP connection: A is used for INET
(IPv4 addresses) and AAAA is used for INET6 (IPv6 addresses).

New argument FAMILY can be used to request particular RR type.  Its
possible values are:

     'RESOLVE_DFL'
          Look for 'A' or 'AAAA', depending on the connection type.
          This is the default.

     'RESOLVE_IP4'
          Resolve to IPv4 addresses ('A' records).

     'RESOLVE_IP6'
          Resolve to IPv6 addresses ('AAAA' records).

* New functions

** string is_ipstr(string S)

Returns 1 if S is a string representation of an IP address (IPv4 or
IPv6).

** string is_ip4str(string S)

Returns 1 if S is a string representation of an IPv4 address.

** string is_ip6str(string S)

Returns 1 if S is a string representation of an IPv6 address.

** string reverse_ipstr(string IP)

Returns a reversed representation of the IP address, suitable for
use in DNS labels.

** string tr(string SUBJ, string SET1, string SET2)

Transliterates characters in SUBJ by replacing all occurrences of the
characters found in SET1 with the positionally corresponding characters
in SET2.  Character ranges ('a-z') are allowed in both sets.  A character
range in SET1 translates to a corresponding character from the range in
SET2, e.g. tr(x, 'a-z', 'A-Z') translates string x to uppercase.

Character classes ([a-z], [[:alpha:]], etc) are allowed in SET1 and
translate to the corresponding single character from SET2, e.g.
tr(x, '[[:digit:]]', '_') replaces all decimal digits in string x with
underscores.

** string dc(string SUBJ, string SET)

Deletes from SUBJ characters that appear in SET.  The syntax of SET is as
described for SET1 above.

** string sq(string SUBJ, string SET)

"Squeeze repeats".  Replaces each sequence of a repeated character
that is listed in SET, with a single occurrence of that character.

* Changes in match_cidr function.

The match_cidr function is re-implemented as a built-in.

The module match_cidr.mfl is deprecated.

* Deprecated MFL modules

The following MFL modules are deprecated.  They are retained for
backward compatibility.  Existing code using any of these will compile
and work as in previous releases, except that a warning will be
printed to draw your attention to the fact.  You are advised to remove
any uses of these modules, as they will be removed in future versions:

** match_cidr.mfl

This module is not needed any more.

** is_ip.mfl

This module defines function is_ip() which is superseded by is_ipstr()
built-in (see above).

** revip.mfl

This module defines function revip() which is superseded by
reverse_ipstr() built-in.


Version 8.17, 2023-07-07

* Multiple handler definitions

Multiple "prog" declarations with the same handler name are now
allowed.  Such declarations are processed the same way multiple
"begin" and "end" sections were processed in prior versions:
when compiling the filter program, the code from all "prog"
declarations having the same handler name is combined into one code
block, in the same order the declarations appear in the source
file(s).

This allows MFL modules to define handler snippets.

* New special handler: action

The "action" special handler is executed before communicating the reply
action (accept, reject, etc.) to the server.  The handler takes four
arguments: numeric identifier of the action that is about to be
returned, SMTP response code, extended response code, and textual
message passed along with the action.  The last three arguments are
meaningful only for reject and tempfail actions.

Action handlers can be used for logging or accounting of the executed
actions.

* New variable: milter_state

The milter_state variable is initialized with the numeric code of
the current milter state.  Using this variable a function can execute
code depending on the handler it was called from.

The new module "milter.mfl" defines numeric constants for milter
states.  The functions milter_state_name and milter_state_code can
be used to convert this code to symbolic name and vice versa.

* New functions

The following new functions are provided to convert numeric
identifiers of various MFL entities to strings and vice-versa:

** string milter_state_name (number code)

Returns symbolic name of the milter state identified by its code.

** number milter_state_code (string name)

Returns numeric code of the state identified by its name.

** string milter_action_name (number code)

Returns symbolic name of the reply action identified by its code.

** number milter_action_name (string name)

Returns numeric code of the action identified by its name.

** void dbbreak (number @var{dbn})

Stop sequential access to the database and deallocate all associated
resources.  Use this function if you need to break from the sequential
access loop, e.g.:

  loop for number dbn dbfirst(dbname)
  do
    if some_condition
      dbbreak(dbn)
      break
    fi
  done while dbnext(dbn)

* New module: cdb

The "cdb" (control database) module provides functions for deciding
what MFL action to take depending on the result of a look up in a DBM
file.  Keys in the database have the format "PREFIX:KEY", where PREFIX
is one of:

  email		match sender email
  ip            match sender IP address
  domain        match sender domain part
  subdomain     search for a match among the domain part and its parent 
                domains
  mx            match MX of the sender domain part

Values are (case-insensitive):

  OK            continue executing the MFL code
  ACCEPT        accept the mail
  REJECT	reject the mail (550)
  TEMPFAIL      return a temporary failure (451)
  GREYLIST      greylist the mail

or action specification in the form

  [code [xcode]] text

where code is 3-digit SMTP response code, xcode is extended SMTP code,
and text is explanatory reason text.  Both code and xcode must begin
with '4' or '5'.  If code and xcode are missing, reject the mail with
550 5.1.0 and the given text.

This module exports one function:

  func cdb_check(string prefix, string key)

Depending on the value of the prefix argument it does the following:

  ip
      Look up the "ip:KEY" in the database.  If found, take the action
      as described above.
  email
      Key is an email address.  Obtain its canonical form by
      splitting it into local and domain parts, converting the latter
      to lower case, reassembling the parts back into an email address
      and prefixing it with the string "email:".  Look up the resulting
      string in the database.  Take action indicated by the value.
  domain
      Key is an email address.  Extract its domain part, convert it
      to lower case and prefix it with "domain:".  Look up resulting
      string in the database.  If the look up succeeds, take action
      indicated by the value found.
  subdomain
      Same as above, but in case of failure, strip the shortest
      hostname prefix (everything up to the first dot, inclusively)
      from the domain and restart with the resulting value.  Continue
      process until a match is found or the argument is reduced to empty
      string.
  mx
      Key is an email address.  Extract its domain part.  For each of
      its MX servers, look up the key "mx:SERVER" and, if found, take
      action indicated by the value found.

The cdb_check function returns to caller only if the key was not
found in the database, or the lookup returned "OK" (case-insensitive)
or an empty string.  Otherwise, if the lookup returns an action, this
action will be performed and further execution of the filter code will
stop.

If the looked up value was "GREYLIST" while the function was called
from the handler prior to "envrcpt" (i.e. "connect", "helo", or
"envfrom"), the current handler will return and normal control flow
will resume from the next handler (as if by "continue" action). Actual
greylisting will be performed later, on entry to "envrcpt" handler.

The following global variables control the functionality of the
module:

  cdb_name    Name of the control database file.  Defaults to
              /etc/mail/mfctl.db
  cdb_greylist_interval
              Greylisting time.  Defaults to 900 seconds.

* mtasim: check expected textual replies

The "\E" command accepts optional second argument.  If supplied,
it is treated as an extended regular expression.  The subsequent
command will then succeed if its return code matched the one supplied
as the first argument, and its extended SMTP code and textual message
match the supplied regular expression.

* Bugfixes

** mtasim: correctly pass final body chunk to the milter

** Fix discrepancy between $N and $(N)

Both terms now mean exactly the same: Nth variadic argument.

** fix type conversions of typed variadic arguments

** Milter library: eliminate trailing space from arguments passed to handlers

** Milter server: don't pass extra \0 when sending multiple strings

** Fix handling of reply actions without explicit message text

In previous versions, the reject and tempfail actions would use the
default reply code if called without explicit message text (3rd
argument).


Version 8.16, 2023-05-01

* Support for keyfiles in PKCS#8 format

* Bugfixes

** Fix line numbers in MFL stack trace

** Fix printing of octal numbers (%o) in sprintf

** Fix endless loop in cname chain resolver

The bug would be triggered by cname loops that end in NXDOMAIN.

** Fix out-of-range memory access in dkim_verify

The bug would cause sporadic segmentation violations if the obtained
DNS record was invalid.

Version 8.15, 2022-12-11

* Default MFL source file suffix

The default suffix for MFL files is changed to '.mfl'.  In particular,
the master script file is now "mailfromd.mfl".  This change is
intended to avoid confusion with Metafont files, which have suffix
'.mf'.

As of this version, the new suffix is recommended, but not obligatory:
the legacy '.mf' suffix is still supported.  If a file 'X.mfl' is not
found, mailfromd will look for 'X.mf'.

* MFL module search path

MFL modules loaded using the "require" or "import" statements are
looked up in module search path.  Previously, they were searched for
in include search path, which created confusion, since include
search path is intended for use by preprocessor.  To maintain backward
compatibility, if mailfromd is unable to find a module in module
search path, it will retry the search using include path.  This
behavior will be maintained during a transitional period (a couple of
releases), after which searches in include search path will be
discontinued.

* Preprocessor configuration

Use of preprocessor is configured by the following statement in the
main configuration file:

  preprocessor {
    # Enable preprocessor.
    enable yes;
    # Preprocessor command line stub.
    command "m4 -s";
    # Pass current include path to the preprocessor via -I options.
    pass-includes false;
    # Pass to the preprocessor the feature definitions via -D options
    # as well as any -D/-U options from the command line.
    pass-defines true;
    # Name of the preprocessor setup file.  Unless absolute, it is
    # looked up in the include path.
    setup-file "pp-setup";
  }

If preprocessor.pass-includes is true, the preprocessor.command
setting is augmented by zero or more -I options, thereby supplying it
the mailfromd include path.

Furthermore, if preprocessor.pass-defines is set, zero or more
-D options defining optional features are passed to it (e.g.
-DWITH_DKIM) as well as any -D and -U options from the mailfromd
command line.

Unless the value of preprocessor.setup-file begins with a slash,
the file with this name is looked up in the current include search
path.  If found, its absolute name is passed to the preprocessor as
first argument.

If the value begins with a slash, it is passed to the preprocessor
as is.

* New MFL operator: $@

The $@ operator can be used as the last argument in a call to
variadic function from another variadic function.  It passes
all variable arguments supplied to the calling function on to
the function being called.  E.g.:

    func x(...)
    do
      # do something
    done

    func y(string x, ...)
    do
      x($@)
    done

In this example, if "y" is called as y("text", 1, 2, 3) it will call
"x" as x(1, 2, 3).

This operator can also be used with a numeric argument: $@(N).  In
this case, it will remove first N elements from the argument list and
push remaining ones on stack.  This is similar to the 'shift'
operator in other programming languages, e.g.:

    x($@(2))

* Data types in variadic function declaration

The ellipsis in a variadic function declaration can be preceded by
the data type, e.g.:

  func sum (number ...) returns number

For compatibility with previous versions, if the type is omitted,
string is assumed.

* The void() type cast

The void() type cast can be used around a function call to indicate
that its return value is ignored deliberately.

* mfmod: dynamically loaded modules

This new type of mailfromd modules uses dynamically loaded libraries
to extend the program functionality without having to modify its code.
For a detailed discussion see the manual, section 4.22, "Dynamically
Loaded Modules".

Three mfmods exist at the time of this writing:

  - https://www.gnu.org.ua/software/mfmod_ldap/
    LDAP searches.

  - https://www.gnu.org.ua/software/mfmod_openmetrics
    Open metrics support.

  - https://www.gnu.org.ua/software/mfmod_prce/
    Support for Perl-comparible regular expressions.

* Syntax of special handler definitions

Special handlers ("begin" and "end", in particular) are now defined using
the standard "prog" keyword (similar to milter state handlers):

  prog begin
  do
    ...
  done

  prog end
  do
    ...
  done

Old syntax is supported for backward compatibility, but causes a
deprecation warning.  Application writers are advised to update their
code.

* New special handlers: startup and shutdown

These two handlers provide global initialization and cleanup routines.
The "startup" handler is run by the master mailfromd process as part
of the startup sequence, before the program starts to serve any milter
requests.  The "shutdown" handler is run when mailfromd is about to
terminate.

Notice an important differences between "startup"/"shutdown" and
"begin"/"end" special handlers.  The latter are session specific: they
are run at the start and end of a milter session.  The former are
global: they are run at the program startup and shutdown.

The "startup" handler is normally used by mfmod interface modules to
load the corresponding shared library.

* Use of STARTTLS in callout

If TLS is supported by libmailutils, the SMTP callout code will use
STARTTLS when offered by the remote server.  This is controlled by the
smtp-starttls configuration statement.  Its possible values are:

  never
    Never use STARTTLS.

  always
    Always use STARTTLS if offered by the server.

  ondemand
    Use STARTTLS only if MAIL FROM: command failed with the code
    530 (Authorization required).

The default is "ondemand".

* Qualified DBM file names in database configuration

Argument to database.file statement can be prefixed with "database
scheme" to select alternative DBM implementation.  For example:

  database rate {
     file "gdbm://rate.db";
  }

See the manual, section 7.11 "Database Configuration" for details.

* New command line option: --echo

The --echo option allows you to control where the output of the "echo"
statement goes in "run" and "test" modes.  When used without argument
it directs the output to the standard output stream.  If an argument
is supplied (as in: --echo=FILE), the output goes to the named file.
The file will be created if it doesn't exist.  Notice, that in the
latter case, the use of '=' is compulsory (--echo FILE won't work).

* Deprecated configuration statements removed

Deprecated configuration statements `lock-retry-count' and
`lock-retry-timeout' were removed in this version.  Use
the `locking' statement instead, e.g. instead of

  lock-retry-count 10;
  lock-retry-timeout 1;

write

  locking {
    retry-count 10;
    retry-sleep 1;
  }

* Removed support for obsolete features: legacy GeoIP and DSPAM

Version 8.14, 2022-08-13

* Initialization of implicitly declared automatic variables

Implicitly declared automatic variables are initialized to null
values, just like global ones.  This means, in particular that
the following code is now valid:

  func foo()
  do
    if bar()
       set a "ok"
    fi
    echo a
  done

Depending on the return value of bar(), this function will print
either "ok" or an empty string.  In previous versions, it would
produce unspecified results.

* Buffered I/O

The I/O operations can be buffered.  Use of fully buffered streams
can dramatically improve performance, especially for `getline' and
`getdelim' calls.

The global variables `io_buffering' and `io_buffer_size' define
buffering mode and associated buffer size for file descriptors
returned by the subsequent calls to `open' or `spawn'.  Buffering mode
of an already open file descriptor can be changed using the `setbuf'
function.

The `io_buffering' variable defines the buffering mode.  By
default it is 0 (BUFFER_NONE), which disables buffering for
backward compatibility with the previous versions.  Another
possible values are: 1 (BUFFER_FULL) and 2 (BUFFER_LINE)

When set to BUFFER_FULL, all I/O operations become fully buffered.
The buffer size is defined by the `io_buffer_size' global variable.

BUFFER_LINE is similar to BUFFER_FILE when used for input.  When used
for the output, the data are accumulated in buffer
and actually sent to the underlying transport stream when the newline
character is seen.  The `io_buffer_size' global variable sets the
initial value for the buffer size in this mode.  The actual size can
grow as needed during the I/O.

The default value for `io_buffer_size' is the size of the system page.

The symbolic constants BUFFER_NONE, BUFFER_FULL and BUFFER_LINE are
defined in the 'status.mf' module.  E.g.:

  require status

  begin
  do
    io_buffering = BUFFER_FULL
  done

Use the `setbuf' function to change the buffering mode and/or buffer
size for an already opened stream, e.g.:

  setbuf(fd, BUFFER_FULL, 4096)

* Changes in read and write functions

The 'read' function tries to read as much data (up to the requested
amount) as possible.  It will return success if it succeeded to read
less bytes than requested (in previous versions it would incorrectly
signal the e_io exception in this case).  Use the length() function
to determine actual number of bytes read.  The 'read' functions signals
e_eof if it read 0 bytes and e_io if an error occurred.

The 'write' function tries to write as much data (up to the requested
amount) as possible.  It will signal e_io in case of error and e_eof
if 0 bytes were written.

* dkim_sign and Sendmail

Sendmail silently modifies certain headers before sending the
message in the SMTP transaction.  It has been reported that on certain
occasions this invalidates DKIM signatures created by dkim_sign().
To prevent this from happening, dkim_sign() now mimics the Sendmail
behavior and reformats those headers before signing the message.  The
headers affected are: Apparently-To, Bcc, Cc,
Disposition-Notification-To, Errors-To, From, Reply-To, Resent-Bcc,
Resent-Cc, Resent-From, Resent-Reply-To, Resent-Sender, Resent-To,
Sender, To.

This behavior is controlled by the global variable
dkim_sendmail_commaize.  Set it to 0 to disable it.

* Support for rsa-sha1 in DKIM

Both dkim_sign and dkim_verify support rsa-sha1 for compatibility with
older software.  Upon return from dkim_verify the name of the algorithm
used to sign the message is stored in the global variable
dkim_signing_algorithm.  The dkim_sign function takes additional
optional argument that specifies the algorithm to use.  Its
declaration is now:

  void dkim_sign(string d, string s, string keyfile
                 [, string ch, string cb, string headers, string algo ])

* New DKIM explanation code: DKIM_EXPL_BAD_KEY_TYPE

This code is reported by `dkim_verify' if the `k=' tag of the public
DKIM key contains a value other than "rsa".

* Support for CNAME chains

CNAME chains are formed by DNS CNAME records pointing to another
CNAME.  Using CNAME chains in DNS is not considered a good practice and
prior versions of mailfromd would refuse to resolve a CNAME pointing to
CNAME.  However, this interacted badly with certain DNS servers that
publish otherwise valid RRs pointed to by 2 or 3 element CNAME chains.
To cope with such server, mailfromd now allows for CNAME chains of
length 2 by default.  This can further be configured using the
"max-cname-chain" statement in the "resolver" section of mailfromd
configuration file (see below).

* The "resolver" configuration statement

This new configuration statement configures certain aspects of the
internal DNS resolver.  The syntax is as follows:

  resolver {
    config FILENAME;
    max-cname-chain NUM;
  }

The "config" statements defines the name of the resolver configuration
file to use instead of the default /etc/resolv.conf.

The "max-cname-chain" statement defines the maximum length of a CNAME
chain that will be followed.  The default is 2.

* Bugfixes

** Fixed sorting in dns_query()

** Fixed a bug in message I/O functions

If compiled with mailutils versions newer than 3.13, this bug would
provoke infinite recursion in message_to_stream or its derived
functions.

** Fixed a bug in dkim_sign routine

The bug would cause coredumps on 32-bit architecture.

** Avoid dereferencing undefined optional arguments in built-ins

** Fixed return value of hasmx function

** Fixed header handling in send_text, create_dsn and send_dsn built-ins

** Fixed compilation with flex >= 2.6.1

** Remove unused configuration variables

Version 8.13, 2022-01-02

* Fix compilation with mailutils 3.14

* sed

** fix replacement of the requested Nth pattern instance

This fixes sed expressions like s/X/@/2.

Bug reported in:
https://lists.gnu.org/archive/html/bug-tar/2021-07/msg00000.html

** rewrite regular expression scanner

* SPF: return PermError if more than one record is published

Version 8.12, 2021-08-06

* Filters and filter pipes

A "filter" is a mailutils entity which converts its input to output
using a predefined set of rules.  Filters are used to implement such
basic conversions as base64 and quoted-printable.

A "filter pipe" is a string consisting of filter invocations delimited
by pipe characters ('|').  Each invocation is a filter name optionally
followed by a comma-separated list of parameters.

Filter pipes are passed in string arguments to various MFL functions
in order to perform string data conversions.

Filter pipes are described in detail in the Section 5.7 "Filtering
functions" of the Mailfromd Manual.

* Decoding MIME messages 

Please refer to the subsection 5.18.3, "MIME functions" in the Mailfromd
Manual for a detailed description of the functions below.

** New functions

- string filter_string (string input, string filter_pipe)

  Transforms the string input using filters defined in filter_pipe
  and returns the result. 

- void filter_fd (number src_fd, number dst_fd, string filter_pipe)

  Reads data from file descriptor src_fd, passes it through filters
  defined in filter_pipe and writes the result to the file descriptor
  dst_fd

- string message_content_type (number nmsg)

  Returns the content type of the message or message part, identified by
  its argument.

- number message_body_decode (number nmsg)
  (module mime.mf)

  Decodes the body of the message or message part nmsg.

- number message_part_decode(number nmsg, number part)
  (module mime.mf)

  Decodes the body of the given part of a MIME message.

** Changes to message_body_to_stream

Optional third argument contains a filter pipe, which will be applied
to the data obtained from body before passing it to the output stream.
Special filter "mimedecode" is defined, which decodes the data in
accordance with the message content transfer encoding.  

Version 8.11, 2021-05-26

* Fix operation on big-endian architectures (tested on s390x)


Version 8.10, 2021-02-23

* Use of uninitialized automatic variables

The MFL compiler issues a warning if it encounters the use of a
previously uninitialized automatic variable.  In future versions
the warning will change to error.

* Use of string variables in boolean context

Strings can meaningfully be used in boolean context.  For example

  func f(string s)
  do
    if s
       echo "non-empty
    fi
  done

The use of "s" in conditional is equivalent to

  if s != ""

* Fix uninitialized local variables in dns.mf

Version 8.9, 2020-12-29

* The sed function.

The construct:

  sed(VALUE, SEXPR [, SEXPR...])

where each SEXPR is a sed-like `s' command: s/REGEXP/REPL/[FLAGS]
matches VALUE against the REGEXP.  If the match succeeds, the portion
of VALUE which was matched is replaced with REPL.  If the FLAGS value
includes 'g' (global replace), this process continues until the entire
VALUE has been scanned.

The resulting output serves as input for next SEXPR, if such is
supplied.  The process continues until all arguments have been
applied.

The function returns the output of the last SEXPR.

For example:

  #pragma regex +extended
  set email sed(input, 's/^<(.*)>$/\1/', 's/(.+@)(.+)/\1\L\2\E/')

This removes optional angle quotes and converts the domain
name part to lower case.

* The qr function

The qr function quotes its first argument as a regular expression, by
escaping with a backslash each character that has special meaning in
regular expression (such as '*', '?', etc.)  The set of special
characters is controlled by the `#pragma regex' statement in effect.

* The dns_query function

The dns_query function provides a generalized API for querying the
Internet Domain Name System.  Example usage:

  # The dns module defines the DNS_TYPE_ constants
  require dns
  
  # Send the query and save the reply descriptor
  set n dns_query(DNS_TYPE_NS, domain_name)

  if n >= 0
    # If non-empty set is returned, iterate over each value in it:
    loop for set i 0,
         while i < dns_reply_count(n),
         set i i + 1
    do
      # Get the actual data:
      echo dns_reply_string(n, i)
    done
    # Release the memory associated with the reply.
    dns_reply_release(n)
  fi

* On dns_getname, dns_getaddr, getns, and getmx

These used to be built-in functions.  Starting from this release, they
are implemented in pure MFL, in the module 'dns'.  Be sure to require
this module if you are using these functions.

* New geolocation functions (libmaxminddb)

The support for geolocation using the libmaxminddb library is added.
It is enabled if the libmaxminddb is installed and can be located
using pkg-config.  The new configure option `--with-geoip2' is available
to expressly request it.

If enabled, the GeoIP2 support is indicated by the following line in
the output of configure:

  Enable GeoIP2 support..................... yes

In the output of `mailfromd --show-defaults', it is indicated by the
word GeoIP2 in the list of optional features.

The preprocessor macro WITH_GEOIP2 is defined if the GeoIP2 support is
compiled in.

The following new functions are available:

** void geoip2_open (string FILENAME)

Opens the geolocation database file FILENAME.

** string geoip2_dbname (void)

Returns the name of the geolocation database currently in use.

** string geoip2_get (string IP, string PATH)

Looks up the ip address IP in the database and returns the data item
identified by PATH.  E.g. to retrieve the country code:

   geoip2_get($client_addr, 'country.iso_code')

** string geoip2_get_json (string IP; number INDENT)

Looks up IP in the database and returns entire data set, formatted as
JSON object.

* Legacy geolocation functions

Support for the legacy geolocation library libGeoIP is marked as
deprecated.  Users are advised to migrate to GeoIP2 instead.

Version 8.8, 2020-07-26

* DKIM signing

The new function 'dkim_sign' is available in the 'eom' handler for
signing the current message using DKIM.  The typical use is

  prog eom
  do
    dkim_sign("example.org", "s2048", "/etc/pem/my-private.pem")
  done

* DKIM verification

The 'dkim_verify' function verifies the DKIM signature of the
message.  Example usage:

  require status
  prog eom
  do
    set result dkim_verify(current_message())
    if result == DKIM_VERIFY_OK
      # success
    elif result == DKIM_VERIFY_PERMFAIL
      # signature verification failed
    elif result == DKIM_VERIFY_TEMPFAIL
      # message not signed, the key is not available, or the like.
    fi
  done

* Functions header_delete_nth, header_replace_nth were removed

There's no reliable way to address Nth header in the message using the
Milter API.

* MFL changes

** Enumeration constants

Enumeration constants are defined using the following syntax:

[qualifier] const
do
  name1 [expr0]
  ...
  nameN [exprN]
done

expr0-exprN are optional expressions evaluating to constant numeric
values.  In the absence of exprN, the nameN gets defined to the value
of the previous enumeration item plus one.  expr0 default to 0.

For a detailed discussion, see the manual, section 4.8 "Constants".


Version 8.7, 2019-01-03

* The --callout-socket option

New option --callout-socket=URL instructs mailfromd to use URL to pass
callout requests to the callout server listening on URL. It is
equivalent to the callout-url configuration statement, which it
overrides.

This option is used by mtasim to avoid clobbering the existing callout
sockets when starting new mailfromd instance.

* NS lookup MFL functions

This release implements the following new MFL functions:

number primitive_hasns (string DOM)
  Returns 1 if the domain DOM has at least one NS record and 0
  otherwise. Throws an error if DNS lookup fails.

require 'dns'
number hasns (string DOM)
  Same as above, but returns 0 on DNS lookup failures.

string getns (string DOM ; number RESOLVE, number SORT)

  Returns a whitespace-separated list of all the NS records for
  the domain DOM. If optional parameter RESOLVE is 1, the returned list
  contains IP addresses. Optional SORT controls whether the entries are
  sorted.

* Bugfixes
** Callout functions return true on checking the null return address (<>)
** Arguments in transaction between mailfromd and calloutd are quoted
** Avoid false failures in testsuite due to libadns warnings
** configure --with-dbm=T accepts any T supported by mailutils
** The 'dbdel' built-in silently ignores non-existing keys

Version 8.6, 2018-07-24

* New configure option --with-dbm

This option allows you to select any DBM flavor supported by mailutils
as the default DBM implementation for mailfromd.

* Fix byte compilation of mfl-mode.el

* Minor fixes in DNS resolver

* Case-insensitive comparison of SPF record marker


Version 8.5, 2018-04-13

* Ensure proper integer promotion (was broken on certain 64-bit architectures).

* Ensure case-insensitive comparison of SPF record markers.

* Fix primitive_resolve() and resolve()

* Fix assembling of fragmented TXT records.

* Fix resolving of queries containing invalid characters.

Version 8.4, 2017-11-03

* Requires Mailutils 3.4


Version 8.3, 2017-11-02

* GNU adns required

This version requires the adns resolver library
(https://www.gnu.org/software/adns).

* Removed arbitrary limits on the sizes of DNS RRs

The following configuration statements are removed:

** runtime.max-dns-reply-a

** runtime.max-dns-reply-ptr

** runtime.max-dns-reply-mx

** max-match-mx

** max-callout-mx

* Removed caching of SPF results.

The following MFL global variable have been removed:

** spf_ttl

** spf_cached

** spf_database

** spf_negative_ttl

* New MFL functions

string ptr_validate (string IP)
Tests whether the DNS reverse-mapping for IP exists and
correctly points to a domain name within a particular domain.


Version 8.2, 2017-10-18

The purpose of this release is to simplify packaging with alpha 
version of Mailutils 

* Requires Mailutils 3.1.92 or newer


Version 8.1, 2016-11-09

* Requires Mailutils 3.1


Version 8.0, 2016-11-09

This version is a major rewrite. Main changes:

* Requires Mailutils 3.0

* New daemon calloutd

The calloutd utility is a stand-alone callout daemon.  It allows you
to run sender address verification from a separate server.  See the
section 'Milter and Callout servers' below, for a detailed explanation.

* New utility mfdbtool

In previous versions database management tasks were performed by
mailfromd itself when it was called with appropriate options (--list,
--delete, --expire).  Now these options are gone, and all database
management tasks are carried out by a stand alone utility mfdbtool.

* Changes to mailfromd configuration

** enable-vrfy

The `enable-vrfy' statement enables the use of SMTP VRFY statement
prior to normal callout sequence.  If VRFY is supported by the remote
server, mailfromd will rely on its reply and will not perform normal
callout.

This feature is provided for the completeness sake.  Its use is not 
recommended, because many existing VRFY implementations always return
affirmative result, no matter is the requested email handled by the 
server or not.

** The `listen' statement withdrawn

Use `server milter' statement instead, e.g.:

server milter {
  listen "inet://127.0.0.1:7788";
}

** The `--remove' option withdrawn

** The `backlog' statement

The new `backlog' statement is provided for configuring the size
of the queue of pending connections.  The statement is available in
`server' block, e.g.:

server milter {
  id main;
  listen unix:///var/lib/mailfromd/mailfrom;
  backlog 16;
}

* Changes to MFL

** Initial #!/ comment

If a source begins with `#!/' or `#! /' characters, mailfromd treats
this as a start of a multi-line comment, which is closed by the `!#'
on a line by themselves.

This feature allows for compensating for the deficiences of the
traditional `#!' script magic.  For example, if a mailfromd script
must be invoked with some additional option passed to mailfromd (say
--no-user-conf), it can now be written as:

  #!/bin/sh
  exec /usr/sbin/mailfromd --no-config --run $0 $@
  !#
  
  func main(...)
    returns number
  do
    ...
  done

** The use of % before variable names is no longer supported.

The % is now used as modulo operator (see below).

** New operators

 <<        bitwise shift left
 >>        bitwise shift right
 %         modulo
 
** New pragma prereq

The "#pragma prereq" statement ensures that the version of mailfromd 
used to compile the source file is correct.  It takes version number
as its arguments and produces a compilation error if the actual
mailfromd version number is earlier than that.  E.g.

  #pragma prereq 7.0.94

** New exception e_exists

This exception is emitted by the dbinsert built-in if the requested
key is already present in the database.

** New built-in functions

void _expand_dataseg (number N)

  Expands the run-time data segment by at least @var{n} words.  

number _reg (number r)

  Returns the value of the register @var{r} at the moment of the call.
  Symbolic names for run-time registers are provided in the module
  "_register".

void _wd ([number N])

  Enters a time-consuming loop which waits for N seconds (by default
  -- indefinitely).  Before entering the loop, a diagnostic message is
  printed on the syslog facility "crit", listing the PID of the
  process and suggesting the command to be used to attach to it.

number access (string FILE, number MODE)

  Interface to the access(2) function.  Checks whether the calling
  process can access the FILE using MODE.  Returns true on success.
  
  Symbolic values for MODE" are provided in module "status".

number callout_transcript ([number N])

  Returns the current state of the callout SMTP transcript.

  With argument N, sets the callout transcript to that value (0 -
  disabled, 1 - enabled).

string default_callout_server_url (void)

  Returns the URL of the default callout server.

string fd_delimiter (number FD)

  Returns line delimiter string for file @var{FD}.

void fd_set_delimiter (number FD, string DELIM)

  Sets line delimiter for file FD.

string getenv (string VAR)

  Searches the environment list for the variable VAR and returns its
  value.  If the variable is not defined, raises the e_not_found
  exception.
  
string ltrim (string STR [, string CSET)

  Returns a copy of the input string STR with any leading
  characters present in CSET removed.  If the latter is not given,
  white space is removed (spaces, tabs, newlines, carriage returns, and
  line feeds).

string message_nth_header_name (number MD, number N)

  Returns name of the Nth header in message MD.  If there is no such
  header, the e_range exception is raised.

string message_nth_header_name (number MD, number N)

  Returns value of the Nth header in message MD.  If there is no such
  header, the e_range exception is raised.

void message_to_stream (number FD, number MD[, string FLTCHAIN])

  Copies message MD to stream descriptor FD.  The descriptor must have
  been obtained by a previous call to "open".

  Optional FLTCHAIN supplies the name of Mailutils filter chain,
  through which the data will be passed before writing to FD.

number message_from_stream (number FD; string FLTCHAIN)

  Converts contents of the stream identified by FD to a mail message.
  Returns identifier of the created message.

string message_body_to_stream (number FD, number MD[, string FLTCHAIN])

  Copies body of the message MD to stream descriptor FD.  The
  descriptor must have been obtained by a previous call to "open".

  Optional FLTCHAIN supplies the name of Mailutils filter chain,
  through which the data will be passed before writing to FD.
  
boolean message_body_is_empty (number MD)

  Returns true if the body of message MD has zero size or contains only
  whitespace characters.

  If the "Content-Transfer-Encoding" header is present, its value is used to
  decode body before processing.
 
void replbody_fd (number FD)

  Replaces body of the current message with the content of the stream
  FD.  Use this function if the body is very big, or if it is returned
  by an external program.

  Notice that this function starts reading from the current position in
  FD.  Use rewind() to ensure that entire stream is copied.
 
void rewind (number FD)

  Rewinds the stream identified by FD to its beginning.

string rtrim (string STR [, string CSET)

  Returns a copy of the input string STR with any trailing
  characters present in CSET removed.  If the latter is not given,
  white space is removed (spaces, tabs, newlines, carriage returns, and
  line feeds).
  
void shutdown (number FD, number HOW)

  Interface to the shutdown(2) call.  Causes all or part of a
  full-duplex connection FD to be closed.  FD must be either a socket
  descriptor or a two-way pipe socket descriptor (returned by "open(|&...)"),
  otherwise the call to shutdown() is completely equivalent to close().

  The HOW argument identifies which part of the connection to shut down.

void set_from (string EMAIL[, string ARGS])

  Sets envelope sender address to EMAIL, which must be a valid
  email address.  Optional ARGS supply arguments to ESMTP MAIL
  FROM command.

void send_message (number MD [,
                   string TO, string FROM, string MAILER])

  Send the message identified by descriptor MD.  Optional arguments
  supply recipient email addresses (TO), sender email address (FROM),
  and the URL of the mailer to use.
		   
number spawn (string CMD [, number IN, number OUT, number ERR])

  Runs the command CMD.

  The syntax of CMD argument is the same as for the NAME argument to
  open(), which begins with "|", excepting that the "|" sign is
  optional.

void syslog (number PRIO, string TEXT)

  Sends TEXT to syslog using facility/priority PRIO.
  
number tempfile ([string DIR])

  Creates a nameless temporary file and returns its descriptor.
  Optional DIR specifies the directory where to create the file
  (default - "/tmp").

void unlink (string NAME)

  Unlinks (deletes) the file NAME.  On error, throws the e_failure
  exception.

number vercmp (string A, string B)

  Compares two strings as version numbers.  The result is negative
  if B precedes A, positive if B is later than A, and zero, if they
  refer to the same version.

** message_burst

New function `message_burst' converts an RFC-934 digest message into a
MIME message:

  number message_burst(number nmsg; number flags)

The descriptor of the input message is given as its argument (nmsg).
On success, the function returns a descriptor of the newly created
message.  If the input message is not a digest, the e_format exception
is raised.

The global variable `burst_eb_min_length' sets the minimal length of
the encapsulation boundary for digests.

** spf_mechanism

Upon successful return from spf_check_host (or spf_test_record),
the built-in variable spf_mechanism contains a whitespace-separated
list of mechanisms that were matched when evaluating the query.  This
includes any include: or redirect= statements traversed during
evaluation.  The mechanisms are listed in reverse order (latest first).

** clamav and sieve

These two functions take a descriptor of the message as their first
argument.  The new prototypes are:

 number sieve(number msg, string script ;
              number flags, string file, number line)
 number clamav(number msg, string url)

This change is incompatible with previous versions.

To use these functions in the eom handler, pass current_message
as their first argument, e.g.:

prog eom
do
  if clamav(current_message(), "tcp://127.0.0.1:3344")
    ...

** sa and spamc

New function `spamc' is an improved version of the old `sa' function:

 number spamc(number nmsg, string url, number prec, number command)

Arguments are:

 nmsg    -  descriptor of the message to be processed,
 url     -  URL of the spamd server,
 prec    -  precision,
 command -  command to send to spamd.

Allowed values for command argument are:

 SA_SYMBOLS     Process the message and return 1 or 0 depending on
                whether it is diagnosed as spam or not.  Store
                SpamAssassin keywords in the global variable
	        sa_keywords.
 SA_REPORT      Process the message and return 1 or 0 depending on
                whether it is diagnosed as spam or not.  Store entire
                SpamAssassin report in the global variable
	        sa_keywords.
 SA_LEARN_SPAM  Learn the supplied message as spam.
 SA_LEARN_HAM   Learn the supplied message as ham.
 SA_FORGET      Forget any prior classification of the message.

 The function `sa' is rewritten as a wrapper over `spamc'

** open

The open call now supports the "|<" prefix to its first argument:

   set fd open("|< progname arg")

It starts the program with its stdin closed and stdout open for
reading.

The usual stderr redirection is allowed between the '<' and the
command line.
 
** New M4 macros

New macro `string_list_iterate' is provided to compensate for the lack
of array data type in MFL.  The macro splits its argument into
segments separated by a supplied delimiter and, for each segment,
executes MFL code given as its last argument.  For example:

  string_list_iterate(path, ":", seg, `
     if access(seg, F_OK)
       echo "%seg exists"
     fi')

This code treats the `path' argument as a UNIX path string.  Each
directory component is tested for existence and is output if the
test succeeds.
 
** New library functions

require 'callout'
number callout(string EMAIL)

require 'callout'
number callout_open(string URL)

require 'callout'
void callout_close(number FD)

require 'callout'
number callout_do(number FD, string EMAIL[, string REST])

require 'header_rename'
void header_prefix_pattern (string PATTERN[, string PREFIX])

  Rename all headers matching PATTERN (see glob(7)) by prefixing them
  with PREFIX.  

  If prefix is not given, remove such headers.
  
require 'header_rename'
void header_prefix_all (strin NAME[, string PREFIX])

  Rename all headers with given NAME by prefixing them
  with PREFIX.  If prefix is not given, remove such headers.
 
** debug_spec changed signature 

** listens and portprobe

The `listens' function was moved to the `portprobe' module.  It is
actually an alias to the `portprobe' function.  If your filter uses
`listens', require the `portprobe' module.

** _pollhost, _pollmx, stdpoll, strictpoll

These functions have been moved to the `poll' module, which must be
required prior to using any of them.

** message_header_count

This function takes an optional string argument:

  number message_header_count (number NMSG [, string NAME])

If NAME is supplied, only headers with this name are counted.  

* mtasim

Mtasim now sends SMFIC_CONNECT (i.e. invokes the "connect" handler).
Unless connection parameters are supplied, the handler is called with
family 0 (FAMILY_STDIO) and "localhost" as the host name.

Connection parameters can be supplied from the command line (using the
--sender-sockaddr option), or from the interactive shell, using the
\S command.  See documentation, chapter 12 "`mtasim' -- a testing
tool", for a detailed discussion.

* Bugfixes

** Next in do-while loops

The `next' keyword bypassed conditional when used in a do-while
loop, making it effectively endless.  This is fixed. 


Version 7.0, 2010-08-07

* Incompatible changes

The following features, that had been marked as deprecated in 6.0, are
now removed:

 - old-style functional notation
 - the use of functional operators
 - implicit concatenations
 - #pragma option
 - #pragma database

* Milter and Callout servers

This release introduces a notion of a `server', i.e. a special 
`mailfromd' entity responsible for handling a particular task.
Two kinds of servers are supported: Milter servers, which handle
the milter requests, and Callout servers, which run callout
(or sender verification) SMTP sessions and update the cache 
database accordingly. 

When a callout server is enabled, sender verification functions
work the following way.  First, the usual sender verification is
performed with a set of so-called `soft' timeout values.  If
this verification yields a definite answer, that answer is stored
in the cache database and returned to the calling procedure as
usual.  In that regard, this release works exactly as its predecessors
did.  If, however, the verification is aborted due to a timeout, 
the caller procedure is returned the e_temp_failure exception, and 
the session is scheduled for processing by a callout server.  The
latter processes the request using a set of `hard' timeouts, 
which are normally much longer than `soft' ones (their default values
are those required by RFC 2822; see below for a detailed description).
This callout session runs independently of the milter session that
initiated it and which, having initiated the callout, returns a
temporary error to the sender, thereby urging it to retry the connection
later.  In the meantime, the callout server has a chance to finish the
requested sender verification and store its result in the cache
database.  When the sender retries the delivery, the milter server
will obtain the already cached result from the database.  If the
callout server has not finished the request by the time the sender
retries the connection, the latter is again returned a temporary
error, and the process continues until the callout is finished.

Milter servers are declared using the following configuration
statement:

server <type: milter | callout> {
  # Server ID.
  id <arg: string>;
  # Listen on this URL.
  listen <url: string>;
  # Maximum number of instances allowed for this server.
  max-instances <arg: number>;
  # Single-process mode.
  single-process <arg: boolean>;
  # Reuse existing socket (default).
  reuseaddr <arg: boolean>;
  <acl-statement>
}

If the type is `callout', the `server' block statement may also contain the
following sub-statement:

  default <arg: boolean>;

When arg is `yes', this server is marked as the default callout server
for all milter servers declared in the configuration.

Alternatively, you may use a remote callout server run by a separate
daemon 'calloutd'.  In that case, the URL of a callout server is
declared using the `callout-url' statement:

  callout-url <url: string>;

* Timeout control for callout SMTP sessions

Callout SMTP sessions initiated by polling functions are controlled
by two sets of timeouts: `soft' and `hard'.  Soft timeouts are used
by the mailfromd milter servers.  Hard timeouts are used by callout
servers.  When a soft timeout is exceeded, the calling procedure is
delivered the e_temp_failure exception and the session is scheduled for
processing by a callout server.  The latter re-runs the session using
hard timeouts.  If a hard timeout is exceeded, the address is marked
as `not_found' and is stored in the cache database with that status.

Normally, soft timeouts are set to shorter values, suitable for use
in MFL scripts without disturbing the calling SMTP session.  Hard
timeouts are set to large values, as requested by RFC2822, which
guarantee obtaining a definitive answer (see below for the default
values).

Individual timeouts may be set in the configuration file using the
following statement:

smtp-timeout [soft | hard] {
  # Initial SMTP connection timeout.
  connection <time: string>;
  # Timeout for initial SMTP response.
  initial-response <time: string>;
  # Timeout for HELO resonse.
  helo <time: string>;
  # Timeout for MAIL response.
  mail <time: string>;
  # Timeout for RCPT response.
  rcpt <time: string>;
  # Timeout for RSET response.
  rset <time: string>;
  # Timeout for QUIT response.
  quit <time: string>;
};

The default timeout settings are:

 Timeout            Soft     Hard
 ---------------------------------
 connection         10s       5m 
 initial-response   30s       5m
 helo               I/O       5m
 mail               I/O      10m
 rcpt               I/O       5m
 rset               I/O       5m
 quit               I/O       2m

The entries marked with I/O, unless set explicitly by a
corresponding `smtp-timeout soft' entry, are set to the
value of I/O timeout (see the `io-timeout' configuration
statement and the `--timeout' command line option), which
defaults to 3s.

* Automatic export of the "i" macro.

The "i" Sendmail macro is automatically requested for the lowest
used stage handler.  This ensures the log messages are marked with
the corresponding queue ID.

Notice, however, that the MTA is free to honor or ignore the request.
Generally speaking, this works well with Sendmail starting from 8.14.0
and MeTA1 starting from 1.0.PreAlpha29.0.  The "i" macro is almost useless
with Postfix 2.6 or higher, because it defines it only at the EOM stage.

* Language changes

** Use of % in front of identifiers

It is no longer necessary to use % in front of an identifier.  To
reference a variable, simply use its name, e.g.:

   set x var + z

However, old syntax is still supported, so the following statement
will also work:

   set x %var + %z

It will, however, generate a warning message.   

Of course, the use of % to reference variables within strings remains
mandatory.

** User-defined exceptions

In addition to the built-in exception codes, you may define your
own exceptions.  This is done using the `dclex' statement.  For
example:

  dclex myerror

This statement declares a new exception identifier `myerror'.  This
identifier may then be used in `catch' and `throw' statements, e.g.:

  throw myerror "My error encountered"

For a detailed discussion, see the manual, subsection 4.19.2
"User-defined Exceptions".

** The try-catch construct

This version introduces a `try-catch' construct similar to that used
in another programming languages.  The construct is:

  try
  do
    STMTLIST-1
  done
  catch EX-LIST
  do
    STMTLIST-2
  done

where SMTLIST-1 and STMTLIST-2 are lists of MFL statements and EX-LIST
is a list of exceptions.  The control flow is as follows.  First, the
statements from STMTLIST-1 are executed.  If the execution finishes
successfully, control is passed to the first statement after the
`catch' block.  Otherwise, if an exception is signalled and this
exception is listed in EX-LIST, the execution is passed to the
STMTLIST-2.

The `try-catch' construct allows a better and more flexible error
recovery.

For a detailed discussion, see the manual, subsection 4.19.3
"Exception Handling".

** Handling of stderr in open("|...")

If the open function is used to start an external program (i.e. the
argument to open() begins with a `|' or `|&'), the standard error of
the program is closed prior to starting it.  The following special
constructs are provided for redirecting it to an output file or syslog:

- "|2>null: COMMAND"
Standard error is redirected to /dev/null.

- "|2>file:NAME COMMAND
Standard error is redirected to the file NAME.  If the file exists,
it will be truncated.

- "|2>>file:NAME COMMAND
Standard error is appended to the file NAME.  If file does not exist,
it will be created.

- "|2>syslog:FACILITY COMMAND"
- "|2>syslog:FACILITY.PRIORITY COMMAND"
Standard error is redirected to the given syslog facility and,
if specified, priority.  If the latter is omitted, LOG_ERR
is assumed.

** Message Modifications and Accept.

Calling `accept' undoes any modifications to the message applied by,
e.g., header_add and the like.  This is due to requirements of the
Milter protocol.

This behavior caused several false bug reports in the past.  Starting
with this version, calling `accept' after any modifications to the message
results in the following warning message:

  RUNTIME WARNING near /etc/mailfromd.mf:36: `accept' causes previous
  message modification commands to be ignored; call mmq_purge() prior
  to `accept', to suppress this warning

It is only a warning and the `accept' action itself is, of course, honored.
If you see this diagnostics in your log, do the following:

 - if the behavior was intended, call mmq_purge, as suggested (see
   below for a description of this function);
 - if it was not, read the manual, section 5.8, "Message
   Modification Queue", for information on how to handle it.

** #pragma miltermacros

The new `#pragma miltermacros' declares macros that are referenced at a
given stage.  It is helpful when automatic macro negotiation 
is in use and mailfromd is unable to trace all macros referenced from
each handler, i.e. when at least one of the handlers:

- calls functions that reference MTA macros;
- refers to macros via macro_defined() and getmacro() functions. 

See the manual, subsection 4.2.5, "Pragma miltermacros", for a
detailed description.

** MFL functions

*** progress

The `progress' function notifies the MTA that the filter is still
processing the message and urges it to restart its timeouts.  It
is available only in the `eom' handler.

*** sleep

The `sleep' function takes an optional second argument.  If given, it
specifies the number of microseconds to wait.  For example, to sleep
for 1.5 seconds, use:

   sleep(1,500000)

*** dequote

string dequote(string email)

The function `dequote' removes angle brackets surrounding its
argument and returns the resulting string.  If there are no angle
brackets, or if they are unbalanced, it returns unchanged argument.

*** debug_spec

string debug_spec([string modnames[, number minlevel]])

Returns the current debugging level specification.  Optional parameters
supply conditions for abridging the amount of information returned.

The `minlevel' parameters instructs the function to return only those
specifications that have the level part greater than or equal to the
given value.  The `modnames' parameter (a comma-separated list of
module name parts) selects only those specification that match the
supplied module names.

*** mmq_purge

The function `mmq_purge' purges internal message modification queue.
This undoes the effect of the following functions, if they had been
called previously: rcpt_add, rcpt_delete, header_add, header_insert,
header_delete, header_replace, replbody, quarantine.

** New built-in constant `__git__'.

The `__git__' built-in constant is defined for alpha versions only.
Its value is the GIT tag of the recent commit corresponding to that
version of the package.

* smap

The smap utility has been removed.  A new project was established
that provides and largely expands its functionality.  See
http://smap.software.gnu.org.ua, for additional information,
including links to file downloads.

* Version output for alpha versions.

Starting from this release, all alpha versions output
additional information when invoked with the `--version' option.
The new output looks like this:

       mailfromd (mailfromd) 6.0.91 [release-6.0-17-ga3fa5da]

where the string between brackets is the recent GIT tag (see also
the description of `__git__' constant above).  If this release
contains some uncommitted changes, the suffix `-dirty' is appended
to it.

* mtasim

New option --milter-timeout sets timeouts for Milter I/O operations.


Version 6.0, 2009-12-12

* Overview

  This release is aimed to fix the logical inconsistencies that  
affected the previous versions, in preparation to the new major
release that will follow.  Some features that have been previously
declared as deprecated are now removed, whereas some obsolete features
are marked deprecated now and will be removed in the future version.
These changes are described in the chapter `Incompatible changes'.

  A special mechanism is provided to facilitate migration to the new
syntax.  It is described in chapter `Upgrade procedure'.  Please read
it carefully before upgrading.

* Incompatible changes
  
  Historically, the filter script file contained both the actual filter
source code, and run-time configuration directives for mailfromd (in
the form of `#pragma option' and `#pragma database' statements). Such
a mixture of concerns is counter-productive in the long run.

  Starting from version 6.0 the two concerns are separated.  The filter
source code is kept in the file `$sysconfdir/mailfromd.mf' (see
below), and the run-time configuration is provided by the
configuration file `$sysconfdir/mailfromd.conf'. (see the docs,
chapter "Mailfromd Configuration"). Thus, changing run-time
configuration does not imply changing the filter program itself and
vice-versa. This allows to implement a full-fledged module system.

  Consequently, the `#pragma option' and `#pragma database'
statements are deprecated.

  In previous versions, the filter script file had the `.rc' suffix.
This was wrong, because this suffix usually marks a configuration
file, which `mailfromd.rc' was not.  Starting with this release the
script file is renamed to `mailfromd.mf'.  For compatibility reasons,
in the absence of this file, the legacy file `mailfromd.rc' is
recognized and parsed.

** Pies withdrawn

The `pies' utility has been removed from the package.  It is moved
into a stand-alone package called `Pies'.  See
http://pies.software.gnu.org.ua, for more information about the
package, including pointers to file downloads.

** Unquoted literals

The use of unquoted literals is no longer allowed.

** Unnamed parameters and short type names in function declarations

The following style of function declarations is deprecated:

  func foo(string,number)

The use of first letter instead of the full type name is deprecated
as well.

** Operational notation

Historically, MFL allowed to call functions of single argument using
operational notation, i.e. to write:

   foo 2

instead of

   foo(2)

Such a usage is deprecated and its support will be discontinued
in future versions.

** Implicit concatenation

Implicit concatenation of variables (e.g. `%bar %baz') is still
supported but issues a deprecation warning.  It will be removed in
future versions. Use `.' operator instead.  See `Explicit
concatenation', below.

Notice, however, that this change does not affect adjacent
literals, which are implicitly concatenated as before.  In other
words, the following statement is OK:

  set foo "string" "ent test"

but the following is not:
  
  set foo %bar %baz

It should be written as

  set foo %bar . %baz

** #require

The `#require' keyword is deprecated.  Use `require' instead.
See `Module system', for details.

** message_read_line, message_read_body_line and EOF

These functions raise EOF exception if there are no more lines to read.
In previous version, e_io was signalled in this case.

* Upgrade procedure

  To remove the deprecated features from your scripts and upgrade them
for the new configuration system, follow the steps below:

1. Run `mailfromd --lint'.  It will show a list of warnings,
similar to this (though, perhaps, much longer):

  mailfromd: Warning: using legacy script file
    /usr/local/etc/mailfromd.rc
  mailfromd: Warning: rename it to /usr/local/etc/mailfromd.mf
    or use script-file statement in /usr/local/etc/mailfromd.conf
    to disable this warning
  mailfromd: /usr/local/etc/mailfromd.rc:19: warning: this pragma is
    deprecated: use relayed-domain-file configuration statement instead
  mailfromd: /usr/local/etc/mailfromd.rc:23: warning: this pragma is
    deprecated: use io-timeout configuration statement instead
  mailfromd: Info: run script /tmp/mailfromd-newconf.sh
    to fix the above warnings

2. At the end of the run mailfromd creates a shell script
named `/tmp/mailfromd-newconf.sh'.  To fix the above warnings,
run this script:

$ sh /tmp/mailfromd-newconf.sh

It will edit and patch all MFL sources that need upgrading.  A backup
copy of each source file will be created.  The name of each backup
file is constructed by appending `.bak' to the original file name.

3. Now retry `mailfromd --lint'. It should show no warnings now.
Remember, that your script file is now named `mailfromd.mf'.

* New features

** Explicit concatenation

The concatenation of two string operands is indicated by the `.' (dot)
operator between them:

   set boo %bar . %baz

Implicit concatenation (e.g. `%bar %baz') is still supported but
issues a deprecation warning.  It will be removed in future versions.

** Explicit type casts

The syntax for an explicit type cast is: TYPE(EXPR), where TYPE is
the corresponding type name, e.g.:

  set val string(10 + %a)
  
** Module system

A module is a logically isolated part of code that implements a
separate concern or feature.  Each module occupies a separate
compilation unit (i.e. file).  The functionality provided by
the module is incorporated into the main program by "requiring"
this module or by "importing" the desired components from it.
To require a module, use the following syntax:

  require MODNAME

where MODNAME is the name of the module, which corresponds to the
name of its compilation unit, without the `.mf' suffix. Unless MODNAME
is a valid identifier in MFL, it should be enclosed in quotes (single
or double).  Note, that the old syntax `#require FILENAME' is
deprecated but it still supported (see `Upgrade procedure', below).

To import a subset of symbols from a module, use the following
syntax:

  from MODNAME import NAMES.

where MODNAME is as described above, and NAMES is a comma-separated
list of the symbol names to import.  Note that the final dot is
mandatory.  Each NAME may also be a regular expression, in which case
only those symbols that match the expression are imported, or a transform
expression, which allows to rename imported symbols on the fly.  See
Mailfromd Manual, subsection 4.20.1, "Declaring Modules", for a
detailed description of the import syntax in general and transform
expressions in particular. A couple of examples to illustrate the
concept:

1) from A import foo,bar.

From module A (file A.mf) import symbols foo and bar.  The importing
module can then refer to these symbols by their name.

2) from A import '/foo.*[0-9]/'.

From module A (file A.mf) import all symbols that match the regular
expression between //.

3) from A import '/foo.*[0-9]/s/.*/my_&/'.

From module A import all symbols that match the given regular
expression and rename them, by prefixing each of them with the string
'my_'. Thus, e.g. function `foo_1' becomes `my_foo_1', etc.

** Module declaration

A module is declared using the following syntax:

module MODNAME [INTERFACE-TYPE].

The final dot is mandatory.  The optional INTERFACE-TYPE defines the
type of the module interface.  If it is `public', then all the symbols
declared in this module are made public (importable) by default,
unless explicitly declared otherwise (See `Symbol scope', below).
If it is `static' all symbols, not explicitly marked as public, become
static by default.  Default is `public'.

The module definition is terminated by the logical end of its
compilation unit, i.e. either by the end of file, or by the
keyword `bye' (see below), if it is used.

** The `bye' keyword.

Special keyword `bye' may be used to prematurely end the current
compilation unit before the physical end of the containing file.
Any material between `bye' and end of file is ignored by the compiler.

** New built-in constant `__module__'

The `__module__' constant keeps the name of the current module.
For the main script file, its value is "top".

** Symbol scope

The qualifiers `static' or `public' may be used in front of the
declaration to set the scope of visibility of the symbol.  Symbols
defined as `static' are visible only within the current module,
whereas the ones declared as `public' are visible outside as well.
The default scope is declared in the module declaration (see below).
Examples:

  static const ONE 1
  public func foo()

See also `Precious variables', below.
  
** Global variables and Milter abort

When Milter abort request is received, all global variables,
excepting precious ones (see below), are reset to their initial
values. In particular, this occurs when the MTA receives the RSET
command.

** Precious variables

A new keyword "precious" may be used in front of a variable
declaration to inform Mailfromd that this variable must retain
its value across Milter abort requests. For example:

  precious number rcpt_counter

  prog envrcpt
  do
    set rcpt_counter %rcpt_counter + 1
  done

In this code, the value of rcpt_counter variable will reflect the
total number of SMTP "RCPT TO" commands received during this session,
including those that have been cancelled by RSET commands.

`Precious' may be combined with a scope qualifier.  In that case the
order of their appearance is irrelevant.  E.g. the two declarations
below are equivalent:

  static precious string rcpt_list
  precious static string rcpt_list

The following built-in variables are implicitly declared as precious:
ehlo_domain, mailfrom_address, milter_client_family,
milter_client_address, milter_server_family, milter_server_address.

* New built-in variables

** number milter_client_family
Address family of the client connection.

** string milter_client_address
Address (IPv4 or UNIX socket) of the Milter client.

** number milter_server_family
Address family of the Milter server socket.

** string milter_server_address
Address (IPv4 or UNIX socket) the server socket is bound to.

* Changes to MFL functions
** getmx

The host names or IPs in the getmx return are sorted in order of
increasing MX priority.

** is_greylisted

If the `is_greylisted' function returns 1, it sets the global
variable `greylist_seconds_left' to the number of
seconds left to the end of greylisting period.

* Bugfixes
** ismx function correctly handles MX names that have more than one A records.


Version 5.2, 2009-08-27

* `next' statement

The definition of `next' statement has been fixed to match `continue'
in other programming languages.  Namely, `next' passes control to
STMT2 in the loop definition:

  loop for STMT1, while EXPR1, STMT2

* Process titles.

The process titles visible in the output of the ps(1) command reflect
the actual states of the corresponding mailfromd subprocesses. For
example:

$ ps axw|grep mailfromd
11251 ?   S      0:00 mailfromd: n5AIs7aL019522: MAIL FROM <foo@ephi.net> SIZE=1417 BODY=8BITMIME
19980 ?   S      0:00 mailfromd: n5AJ5kFO021484: aborting
30497 ?   S      0:00 mailfromd: HELO s6.newveoron.com

* GeoIP support

Two new built-in functions are added to the MFL:

- string geoip_country_code_by_addr(string ip[, bool tlc])

This function looks up the country code by IP address in string form.

- string geoip_country_code_by_name(string name[, bool tlc])

This function looks up the country code by host name.

By default both functions return 2 letter country code (ISO 3166-1
alpha-2).  When a non-zero value is given as the `tlc' argument,
these functions return 3 letter country code (ISO 3166-1 alpha-3).

Both functions raise the `e_not_found' exception if they fail to
determine the country code.

The GeoIP functions are available only if the GeoIP library
(see http://www.maxmind.com/app/c) is installed on the host.

Applications may test whether the GeoIP support is present and
enable corresponding code blocks conditionally by testing if 
the `WITH_GEOIP' m4 macro is defined.  E.g.:

m4_ifdef(`WITH_GEOIP',`
  add "X-Originator-Country" geoip_country_code_by_addr($client_addr)
')

* The gethostname function

The gethostname function takes an optional argument:

  string gethostname ([bool FQN])

If FQN is specified and is `true', the function attempts to determine
a fully qualified host name.

* The localdomain function

New function is defined in the library module `localdomain':

  string localdomain()

It returns the domain name of the box mailfromd is executed on.
It is more reliable than getdomainname, because it uses DNS to
determine the fully qualified domain name.

* `Safedb' functions.

Two new `safedb' interfaces are implemented:

 string safedbmap (string db, string key [, string defval, number null])
 void safedbdel (string db, string key [, number null])

A new global variable is added, which controls the verbosity of all
safedb functions.  If the variable safedb_verbose is set to 1, these
functions log the detailed diagnostics about intercepted exceptions
before returning to the caller.

* `Open' function

The `open' function can be used to connect to TCP/IP sockets.  To
do so, its first argument must be a valid socket URL prefixed with
`@'.  E.g.:

  number fd open("@ inet://127.0.0.1:25")

The I/O operations on `fd' will write to and read from the opened socket.

* System user database functions

These functions provide interfaces to corresponding POSIX calls:

- string getpwnam (string NAME)
- string getpwuid (number UID)

The return value is the string in the usual /etc/passwd format.
If argument is not found in the system password database, these
functions raise the e_not_found exception.

In addition, the following two functions are provided for checking
whether the given key is present in the system password database:

- boolean mappwnam (string NAME)
- boolean mappwuid (number UID)

These functions never raise exceptions.
 
* New I/O functions

- string read (number RD, number N)

Reads N bytes from the resource descriptor RD.

- string getdelim (number RD, string DELIM)

Reads the string terminated by DELIM from the resource descriptor RD.
DELIM must contain exactly one character.

* Sockmap functions

The sockmap.mf module provides functions for interfacing with MeTA1
"sockmaps":

- string sockmap_lookup(number FD, string MAP, string ARG)
- string sockmap_single_lookup(string URL, string MAP, string ARG)

* pies

Signals can be specified in tag list of `return-code' statement.
A signal is given either by its name, or as SIG+n, where n is
its number.  Valid signal names are: SIGHUP, SIGINT, SIGQUIT, SIGILL,
SIGTRAP, SIGABRT, SIGIOT, SIGBUS, SIGFPE, SIGKILL, SIGUSR1, SIGSEGV,
SIGUSR2, SIGPIPE, SIGALRM, SIGTERM, SIGSTKFLT, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGXCPU, SIGXFSZ,
SIGVTALRM, SIGPROF, SIGWINCH, SIGPOLL, SIGIO, SIGPWR, SIGSYS.

Examples of usage:

  return-code (SIGABRT, EX_USAGE) {
    ...
  }

  return-code SIG+6, EX_USAGE {
    ...
  }

New action is allowed in `return-code' block:

  exec COMMAND;

It executes the given COMMAND before other actions. 
  
* Debugging

New function mailutils_set_debug_level allows to set global Mailutils
debug level from your MFL scripts.  This is useful for debugging
scripts that use mailbox or message accessing functions.


Version 5.1, 2009-05-13

* Milter v6.

The version 6 of Milter protocol is implemented, which is compatible
with Sendmail 8.14.0 and newer.  While being backward compatible with
the earlier versions, it allows you to use the new `prog data'
handler.  It also supports macro negotiation, a feature that enables
Mailfromd to ask the MTA to export the macros it needs for each
particular handler.  This means that if you are using Sendmail 8.14.0
or higher (or Postfix 2.5 or higher), you no longer need to worry about
exporting macro names in sendmail.cf file.

The same feature is also implemented on the server side, in mtasim and
pmult.  Consequently, using `define-macros' in pmult configuration file
is not strictly necessary.  However, keep in mind that due to the
specifics of MeTA1, the number of symbols that may be exported for
each stage is limited (Mailfromd manual, section 11.1.2).

* Reject and tempfail actions: Functional notation

The reply actions `reject' and `tempfail' allow functional notation,
i.e. their arguments can be supplied as to a function:

  reject(550, 5.7.7, "IP address does not resolve")

An important feature of this notation is that all three arguments are
MFL expressions, which means that you can now compute the reply codes
at run time:

  reject(550 + %n, "5.7." %x, "Transaction rejected")

An argument can be omitted, in which case the default value is used, e.g.:

  reject(550 + %n, , "Transaction rejected")
  
* New functions

A set of new functions is added that allow to access the headers
from the current message in a uniform fashion.  These functions are
available in the following handlers: eoh, body, eom.

- number current_header_count([string name])

Return number of headers in the current message.  With an argument -
return number of headers that have this name.

- string current_header_nth_name(number n)

Return the name of the nth header.  N is 1-based.

- string current_header_nth_value(number n)

Return the value of the nth header.  N is 1-based.

- string current_header(string name[, number index])

Return the value of the named header, e.g.:

  set s current_header("Subject")

Optional second argument specifies the header instance, if there are
more than 1 header of the same name, e.g.:

  set s current_header("Received", 2)


Index is 1-based.

All current_header functions raise the e_not_found exception if the
requested header is not found.

New system information functions are added:

- string gethostname ()

Return the host name of this machine.

- string getdomainname ()

Return the domain name of this machine.

- string uname (string format)

Return system information formatted according to the format specification.

* New pragma `dbprop'

This pragma defines user database properties.  It takes two or three
arguments:

 #pragma dbprop <pattern> <null> <mode>

where <pattern> is the name of the database or a shell globbing
pattern, <null> is the word "null" if the terminating null byte
is included in the key length, and <mode> is the database file
mode, either in octal or in usual `ls' notation (e.g. rw-r-----).
Either of <null> or <mode> may be omitted.  If both are given, they
may appear in any order.

* Token Bucket Filter

The new function is provided:

  bool tbf_rate(string key, number cost, number interval, number burst_size)

It implements a classical token bucket filter algorithm.  Tokens are
added to the bucket identified by the `key' at constant rate of 1
token per `interval' microseconds, to a maximum of `burst_size' tokens.
If no bucket is found for the specified key, a new bucket is created
and initialized to contain `burst_size' tokens.

For example:

  if not tbf_rate($f "-" ${client_addr}, 1, 10000000, 20)
    tempfail 450 4.7.0 "Mail sending rate exceeded. Try again later"
  fi

This adds a token every 10 seconds with a burst size of 20 and a
cost of 1.  In other words, it allows to sent up to 20 emails within
the first 10 seconds after sending the very first email from the given
email/host address pair.  After that, that pair is allowed to send
at most 1 message per 10 seconds.

One of possible implementations for this function is to limit
the total size of messages tranferred per given amount of time.
To do so, the tbf_rate must be used in `prog eom'.  The `cost'
value must contain the number of bytes in an email (or email bytes
* number of recipients), the `interval' must be set to the number of
bytes per microsecond a given user is allowed to send, and the
`burst_size' must be large enough to accommodate a couple of large
emails.  E.g.: 

  prog eom
  do
    if not tbf_rate($f "-" ${client_addr},
                    message_size(current_message()),
                    10240,   # At most 10 Kb/ms
		    2000000) 
      tempfail 450 4.7.0 "Data sending rate exceeded. Try again later"
    fi
  done

The `tbf_rate' implementation is contributed by John McEleney and
Ben McKeegan.

* Greylisting

A new implementation of the `greylist' function is provided.  In the
contrast to the traditional implementation, which keeps in the
database the time when the greylisting was activated for the given
key, the new one stores the time when the greylisting period is set to
expire.  This implementation allowed to implement the `is_greylisted'
function:

  bool is_greylisted(string key)

which returns True if the `key' is currently greylisted, and False
otherwise.  This implementation is based on the patch by Con
Tassios.

By default, the traditional implementation is used, which ensures
backward compatibility with the previous versions.  To switch to
the new implementation, use the following pragmatic comment at the
beginning of your script:

  #pragma greylist con-tassios
or
  #pragma greylist ct

* The rate builtin

The rate builtin function now takes an optional `threshold' argument:

  number rate(string key, number interval, [number mincnt, number threshold])

If the observed rate (per interval seconds) is higher than the
threshold, the rate function does not increment the hit counters for
that key.  That way messages that were not accepted do not affect the
calculated rate.

Normally, the threshold argument should be equal to the value used in
the right side of comparison operator, e.g.:

  if rate($f "-" ${client_addr}, %rate_interval, 4, %maxrate) > %maxrate
    tempfail 450 4.7.0 "Mail sending rate exceeded. Try again later"
  fi

The threshold argument is made optional in order to provide backward
compatibility with the prior releases of mailfromd.  Nevertheless, its
use is strongly encouraged.  To simplify the task, the new function
`rateok' is provided (see below).
  
* The rateok function

A new library function is provided:

  bool rateok(string key, number sample_span, number threshold; number mincnt)

This is a higher-level interface to the rate function.  This function
returns True if the mail sending rate for `key', computed for the
interval of `sample_span' seconds is less than the `threshold'.
Optional `mincnt' parameter supplies the minimal number of mails
needed to obtain the statistics.  It defaults to 4.

An example of rateok usage follows:

#require rateok

prog envfrom
do
  if not rateok($f "-" ${client_addr}, interval("1 minute"), 40)
    tempfail 450 4.7.0 "Mail sending rate exceeded. Try again later"
  fi
done

This example limits the rate to 40 mails per minute.

* Rate expiration

In addition to the usual expiration algorithm, the rate records are
also expired if no mails were received during a time span greater than
the value of the 2nd argument to the rate (or rateok) function.

* The __statedir__ built-in constant.

The __statedir__ built-in constant is now expanded to the current
value of the program state directory.  In prior releases it used to
expand to the default program state directory.  A new built-in
constant __defstatedir__ is introduced, which expands to the value of
the default program state directory.

* The __preproc__ built-in constant.

Similarly, the __preproc__ built-in constant, which used to signify
the default preprocessor command line, now expands to its current
value.  The new constant __defpreproc__ expands to the default
preprocessor command line.

* Bugfixes
** Second argument to envfrom and envrcpt
** write without third argument
** sa_format_report_header: fix formatting
** Limit use of file descriptors by message capturing eom functions
** fix implementation of `restex' instruction.
** fix inconsistencies in message capturing code.


Version 5.0, 2008-12-26

* Requires Mailutils 2.0 or newer.

* Incompatible changes

** body handler

The type of first parameter ($1) is now generic pointer, not a string.
It can be converted to a usual string using the `body_string' function
(see below).

* Changes to MFL

** Function aliases

Functions can have several names. Alternative function names, or
aliases, are introduced by `alias' statement, placed between the
function declaration and return type declaration, e.g.:

func foo()
alias bar
alias baz
do
  ...
done

Any number of aliases is allowed.

** Functions with variable number of arguments

Ellipsis as the last argument in a list of formal arguments to a
function indicates that this function takes a variable number of
arguments. For example:

  func foo (string a ; string b, ...)

Actual arguments passed in a list of variable arguments have string
data type.  A special construct is provided to access these arguments:

  $(expr)

where expr is any valid MFL expression, evaluating to a number.  This
construct returns exprth argument from the variable argument list.

** getopt and vaptr 

New function `getopt' is provided.

New operator `vaptr' is available for converting function argument
list to the second argument of `getopt'.

* New MFL functions

** rcpt_add(string rcpt)

Adds a recipient to the message envelope.

** rcpt_delete(string rcpt)

Removes the given recipient from the envelope.

** header_add(string hdr, string value [, number index])

Adds a header "hdr: value" to the message.  This function differs from the
`add' action in two regards:

  1. It allows to construct the header name, whereas `add' requires it to
     be a literal string;
  2. Optional `index' argument specifies the location in the header
     list where this header should be inserted.
     
** header_insert(string hdr, string value, number index)

Equivalent to header_add(hdr, value, index).

** header_delete(string hdr [, number index])

Delete header `hdr' from the envelope.  This function differs from the
`delete' action in two regards:

  1. It allows to construct the header name, whereas `delete' requires it to
     be a literal string;
  2. Optional `index' argument allows to select a particular header
     instance to delete.

** header_replace(string hdr, string value [, number index])

Replace the value of the header `hdr' with `value'.  Optional argument
`index' specifies the number of `hdr' instance to replace (1-based).
     
This function differs from the `replace' action in two regards:

  1. It allows to construct the header name, whereas `replace' requires it
     to be a literal string;
  2. Optional `index' argument allows to select a particular header
     instance to replace.

** quarantine(string reason)

Quarantines the message using the given reason.

** replbody(string text)

Replaces the body of the message with the given `text'

** body_string

  string body_string(pointer text, number length)

This function converts a generic pointer to an MFL string.  It can
be used only in `body' handler, e.g. the following fragment collects
the entire message body in a variable and then uses it in the `eom'
handler: 

string text

prog body
do
  set text %text body_string($1,$2)
done

prog eom
do
  echo %text
done

** Macro Access

Two functions are provided for accessing Sendmail macros.

- string getmacro(string name)

Return the value of Sendmail macro `name'.  It is entirely equivalent
to `${name}' construct, except that allows to construct the name
programmatically, while the `${name}' construct requires it to be a
literal string.

- number macro_defined(string name)

Return true if Sendmail macro `name' is defined.

** String functions

- string replstr(string s, number n)
- string sa_format_score(number score, number prec)
- string sa_format_report_header(string report)

** Character type functions

- number isalnum(string s)
- number isalpha(string s)
- number isascii(string s)
- number isblank(string s)
- number iscntrl(string s)
- number isdigit(string s)
- number isgraph(string s)
- number islower(string s)
- number isprint(string s)
- number ispunct(string s)
- number isspace(string s)
- number isupper(string s)
- number isxdigit(string s)

** Mailbox and message manipulation

-  number current_message()
-  void mailbox_append_message(number mbx, number msg)
-  void mailbox_close(number mbx)
-  number mailbox_get_message(number mbx, number nmsg)
-  number mailbox_messages_count(number nmbx)
-  number mailbox_open(string url[, string mode, string perms])
-  number message_body_lines(number nmsg)
-  void message_body_rewind(number nmsg)
-  number message_body_size(number nmsg)
-  void message_close(number nmsg)
-  number message_count_parts(number nmsg)
-  string message_find_header(number nmsg, string header[, number idx])
-  number message_get_part(number nmsg, number idx)
-  bool message_has_header(number msg, string header[, number idx])
-  number message_header_count(number nmsg)
-  number message_header_lines(number nmsg)
-  number message_header_size(number nmsg)
-  bool message_is_multipart(number nmsg)
-  number message_lines(number nmsg)
-  string message_read_body_line(number nmsg)
-  string message_read_line(number nmsg)
-  void message_rewind(number nmsg)
-  number message_size(number nmsg)

** System functions: umask

** string verp_extract_user(string email, string domain)

If `email' is a valid VERP-style email address for `domain', this
function returns the user name, corresponding to that email.
Otherwise, it returns an empty string.

** string sa_format_report_header(string text)

Format a SpamAssassin report `text' in order to include it in a RFC 822
header.  This function selects the score listing from `text', and
prefixes each line with "* ".

** string sa_format_score(number score, number prec)

Format `score' as a floating-point number with `prec' decimal
digits.  This function is convenient for formatting SpamAssassin
scores for use in message headers and textual reports.  It is defined
in module sa.mf.

@smallexample
sa_format_score(5000, 3) @result{} "5.000"
@end smallexample

** Sequential access to DBM

- number dbfirst (string name)
- number dbnext (number dn)
- string dbkey (number dn)
- string dbvalue (number dn)

* Changes to MFL functions

** sa

This function takes an optional third argument, which controls what kind of
data is returned in the sa_keywords variable.  If the third argument
is not supplied or is zero, the sa_keywords variable contains a string
of comma-separated SpamAssassin keywords identifying this message.
This is compatible with previous versions of Mailfromd.

Otherwise, if the third argument is not 0, the value of sa_keywords is
a @dfn{spam report} message.  It is a multi-line textual message,
containing detailed description of spam scores in a tabular form.
The function `sa_format_report_header' can be used to format it for
use in a message header.

** substring

Third argument (`end') can be a negative number, meaning offset from
the end of the string.  Thus:

  substring("mailfrom",4,-1) => "from"
  substring("mailfrom",4,-2) => "fro"

** index and rindex

Both functions take an optional third argument indicating where to
start searching, e.g.:

  index("string of rings", "ring")    => 2
  index("string of rings", "ring", 3) => 10
  
* New global variables.

** last_poll_greeting

Keeps the initial SMTP reply from the last poll.

** last_poll_helo

Keeps the reply to HELO (EHLO) command from the last poll.

* New operation mode.

When given `--run' command line option, mailfromd looks for a function
named `main' and invokes it, passing the rest of command line as its
arguments.  The function `main' must be declared as:

  func main(...) returns number

The return value from this function is used as the exit code.

Command line arguments may be processed using `getopt' builtin function.

* Two stack growth policies.

The stack can be grown either by fixed size blocks, or exponentially.
In first case, the size of the block is divisible by expansion chunk,
which is 4096 words by default.  The expansion chunk size can be
specified as a second argument to pragma stacksize, e.g.:

  #pragma stacksize 10240 8192

Exponential stack growth means that each time the evaluator needs to
have more stack space, it expands the stack to twice the size it had
before.  This growth policy is selected if the word `twice' appears as
the second argument to pragma stacksize:

  #pragma stacksize 10240 twice

All numbers may be suffixed with usual size suffixes (k, m, g, t,
meaning kilowords, megawords, etc).
  
Additionally, maximum stack size may be given as third argument:

  #pragma stacksize 10m twice 200m

* Milter `ports' can be specified using URL notation, e.g.:

  inet://127.0.0.1:1234  instead of inet:1234@127.0.0.1
  unix:///var/run/socket instead of unix:/var/run/socket

* ACLs

Access to Milter can be controlled using access control lists.
  
* Removed depecated features:

 1. Command line options --ehlo, --postmaster-email, and --mailfrom

* mtasim

New command line options `--user' and `--group' allow to specify user
name and a list of additional groups when the program is run with
`root' privileges.

* New programs:

** smap.

Smap is a general-purpose remote map for MeTA1.

** pmult

Pmult is a pmilter to milter multiplexer.  Pmilter is a new filter
protocol implemented in MeTA1, an MTA which should in future replace
Sendmail.  Pmult listens for Pmilter commands from the server,
translates them into equivalent Milter commands and passes the
translated requests to a preconfigured set of Milter filters.  When
the filters reply, the reverse operation is performed: Milter
responses are translated into their Pmilter equivalents and 
are sent back to the server.

Pmult allows to use existing milters with MeTA1 without any
modifications. 

** pies

Pies is a process invocation and execution supervisor.

* GNU Emacs MFL Mode is improved

* Bugfixes
** Fix program evaluator bug that manifested itself on machines where
   sizeof(unsigned long) > sizeof(usnigned).
** Fix stack reallocation.
** Header modification functions affected subsequent messages in the
same SMTP session.  This is fixed.


Version 4.4, 2008-03-10

* The --domain option is withdrawn.

This option was declared as deprecated in version 4.0.  Now it is
withdrawn and its short version (-D) is reused for another purpose
(see -D option, below).

* New command line options -D and -U

Both options work like their m4 counterparts: the `-D' command line
option defines a preprocessor symbol, the `-U' option undefines it.

* Constant vs. variable shadowing

In previous versions of mailfromd name clashes between constants and
variables went unnoticed, which sometimes lead to hard-to-diagnose
errors.  This bug is fixed in this version.  If a constant is defined
which has the same name as a previously defined variable (the constant
"shadows" the variable), the compiler prints the following diagnostic
message: 

<file>:<line>: Warning: Constant name `name' clashes with a variable name
<file>:<line>: Warning: This is the location of the previous definition

A similar diagnostics is issued if a variable is defined whose name
coincides with a previously defined constant (the variable "shadows"
the constant).

In any case, the %NAME notation refers to the last defined symbol, be
it variable or constant.

If a variable shadows a constant, the scope of the shadowing depends
on the storage class of the variable.  For automatic variables and
function parameters, it ends with the final `done' closing the
function.  For global variables, it lasts up to the end of input.

* Exception names.

To minimize chances of name clashes, all symbolic exception codes has
been renamed by prefixing them with the `e_', thus, e.g. `divzero'
became `e_divzero', etc.  The `ioerr' exception code is renamed to
`e_io'.

For consistency, the following most often used codes are available without
the `e_' previx: success, not_found, failure, temp_failure.

The use of old exception codes is still possible by defining a
preprocessor symbol OLD_EXCEPTION_CODES, for example:

  mailfromd -DOLD_EXCEPTION_CODES

* match_dnsbl and match_rhsbl

Both functions malfunctioned in versions from 4.0 up to 4.3.1 due to a
name clash between the exception code `range' and their third
argument.  This is fixed.

Additionally, previous versions of match_dnsbl silently ignored
invalid first argument.  Now, the e_invip exception is signalled in
this case.
  

Version 4.3.1, 2008-03-01

* Fix program evaluator bug that manifested itself on machines where
  sizeof(unsigned long) > sizeof(usnigned).


Version 4.3, 2008-02-10

* write built-in

The `write' built-in function takes an optional third argument,
specifying the number of bytes to write. This form is particualry
useful in `body' handler for writing $1, because it is not null-
terminated, e.g.:

prog body
do
  write(fd, $1, $2)
  ...
done  

* sieve

New built-in function `sieve' provides an interface to Sieve
interpreter.

* Restore previous meaning of --enable-syslog-async.

Unless this option is given to ./configure, asynchronous syslog
implementation will not be compiled.

* Bugfixes:

** Fix compilation on Sun.
** Fix header deletion (delete action).
** Variable shadowing was broken if a rehash happened between vardcl and
   forget_autos.


Version 4.2, 2007-10-23

* Licensed under the GPLv3

* New command line options --syslog-async and --no-syslog-async

These options allow to select the implementation of syslog to use
at run time. 

* RFC 2821 compatibility

The sender verification engine used to send whitespace character
between `MAIL FROM:' and `RCPT TO:' commands and their argument.
This violated RFC 2821, which requires the argument to follow the
command without any intermediate whitespace.  It is fixed in this
release.

* Sample threshold for `rate' function.

The `rate' function takes an optional third argument allowing to
specify the minimum number of received mails needed to obtain the
sending rate value.  The default is 2, which is probably too
conservative. The following example raises it to 10:

  if rate($f "-" ${client_addr}, interval("1 hour"), 10) > %maxrate
    ...
  fi   

* mtasim is improved

In particular, it accepts MAIL FROM: and RCPT TO: without extra space
after the colon, as required by RFC. The milter interface is also
improved. 

* The `resolve' function ignores TXT records.

In other words, resolve and primitive_resolve are guaranteed to return
either an A or a PTR record.
  

Version 4.1, 2007-06-11

* National Language Support.

The program includes National Language Support.  Polish and Ukrainian
translations are available.

* NLS Functions

NLS functions allow to localize your filter scripts for a particular
language.  The following functions are implemented: bindtextdomain,
dgettext, dngettext, textdomain, gettext, ngettext.  In addition, 
macros _() and N_() are also provided.

* GNU Emacs MFL Mode

This release comes with the file `mfl-mode.el', providing MFL mode for
GNU Emacs.  This mode facilitates editing MFL source files.  By
default, the new mode is installed whenever configure determines the
presense of GNU Emacs on your machine.  See the documentation, node
`Using MFL Mode' for the detailed discussion of this mode including
customization information.  

* Input files are preprocessed before compilation.  
  The default preprocessor is M4, but this can be changed (or disabled) at 
configuration time (see `DEFAULT_PREPROCESSOR' variable and 
`--with-preprocessor' command line option).

* New atom $#

  Returns the number of the arguments passed to the function.

* New atom @parm

  Returns the position of parameter `parm' in the function argument
list.  It can be used, for example, to check whether an optional
argument value is passed to the function, e.g.:

func foo(string x; number n)
do
  if $# > @n
    /* `n' is passed */
    ...

  The default preprocessor setup script provides a macro `define'
designed to be used for this purpose:
  
func foo(string x; number n)
do
  if defined(n)
    /* `n' is passed */
    ...

* sprintf

The built-in function `sprintf' is available with the same semantics
as its C counterpart.

* Discontinued support for deprecated features:

** `&code' form to specify an exception code is discontinued.
** pragma options retry, io-retry, and connect-retry
        
* Bugfixes:
** Built-in listen ignored optional second argument.
** Debug specification incorrectly gave preference to the global level
over the source level.  This is fixed, so that `--debug=40,dns=10'
means level 10 for calls from `dns.c', and level 40 for all the rest.


Version 4.0, 2007-05-12

Note for users of 3.1.x: see also the notes for previous alpha
(3.1.9x) versions.

* SIGHUP handling

  SIGHUP instructs `mailfromd' to restart itself.  

* rc.mailfromd reload

  The `reload' option given to `rc.mailfromd' instructs it to send
SIGHUP to the running instance of the program.

* mtasim

  The `mtasim' utility is an MTA simulator for testing and debugging
mailfromd filter scripts.  It supports stdio (-bs) and daemon (-bd)
modes, has GNU readline support and `expect' facility, which makes it
useful in automated test cases.

  See the documentation, chapter `mtasim'.

* `begin'/`end' handlers

  The `begin' and `end' special handlers may be used to
supply startup and cleanup code for the filter program.

  The `begin' special handler is executed once for each
SMTP session, after the connection has been established but
before the first milter handler has been called.  Similarly, an
`end' handler is executed exactly once, after the connection has
been closed.  Neither of handlers takes any arguments.

  See the documentation, section `begin/end'.

* Cache control

  Use function `db_set_active' to enable or disable given cache
database.  E.g.

  # Disable DNS cache:
  db_set_active("dns", 0)
  # Enable it back again: 
  db_set_active("dns", 1)

Similarly, the function `db_get_active' returns a number indicating
whether the given cache database is used or not.   

** Bugfixes
* Fix a long-standing bug in parsing the --predict option argument.  Is there
anybody using this option at all?
  

Version 3.1.91, 2007-04-23

* Non-blocking syslog

This version is shipped with non-blocking syslog implementation by
Simon Kelley.  You may wish to enable it if you noticed that the
number of mailfromd processes grows uncontrollably and the processes
are hung for prolonged amounts of time.  Usually this indicates that
the daemon blocks in syslog() calls.  Read the description of
`--enable-syslog-async' option in chapter `Building' for the detailed
discussion of this (try `info -f doc/mailfromd.info --index-search
syslog-async').

* SPF support

The function check_host() tests the SPF record for the given
identity/host name.  The syntax is:

 number check_host(string ip, string domain, string sender, string helo)

See the documentation, node `SPF functions' for the detailed
description of this function and the related functions and variables.

* next and pass

Use `pass' instead of `next'.

The `next' keyword has changed its semantics: it is now used to
resume the next iteration of the enclosing loop statement (see
below).

For compatibility with the previous versions, its use outside of a
loop statement is still allowed, but a warning is issued.  You are
encouraged to replace all occurrences of `next' in your configuration
scripts with `pass'.

* Loop

The loop statement is implemented.  Its syntax is:

loop [name]
     [for <stmt>,] [while <stmt>,] [<stmt>]
do
     ...
done [while <stmt>]

See the documentation, section `Loop Statements'.

* break and next

The `break' statement exits from the enclosing loop.

The `next' statement resumes the next iteration of the enclosing loop
statement.

Both statements take an optional argument specifying the identifier
(name) of the loop to break from (or continue), this allows to build
complex iterations consisting of nested loops.  For example, in this
code (line numbers added for clarity):

 1   loop outer for set i 1, while %i < %N
 2   do
 3	...
 4	loop for set j 1, while %j < %i
 5	do
 6	   if foo(%j)
 7	     break outer
 8         fi
 9	done
10  done		   		   
11 accept

if the call to `foo' in line 6 returns true, the control is immediately passed
to `accept' in line 11.

* Resizable stack

The runtime stack of the MFL grows automatically as the need arises.
Thus, `#pragma stacksize' sets the initial size of the stack, and
the `Out of stack space' error, which was common in the previous
versions, now can occur only if there is no more virtual memory left.

Whenever the stack gets expanded, mailfromd issues a warning message
to the logs, notifying of the new stack size, e.g.:

    warning: stack segment expanded, new size=8192

You can use these messages to adjust your stack size configuration
settings. 
    
* Runtime stack traces

New command line option --stack-trace enables dumping stack traces
on runtime errors.  This might help localize the source of the error.
The trace looks like:

mailfromd: RUNTIME ERROR near ../mflib/match_cidr.mf:30: invalid CIDR (boo%)
mailfromd: Stack trace:
mailfromd: 0077: test.mf:7: match_cidr
mailfromd: 0096: test.mf:13: bar
mailfromd: 0110: test.mf:18: foo
mailfromd: Stack trace finishes
mailfromd: Execution of the configuration program was not finished

Each trace line describes one stack frame, the lines appear in the
order of most recently called to least recently called.  Each frame
consists of:

1. Value of program counter at the time of its execution
2. Source code location, if available
3. Name of the function called

The same output can be obtained by calling function stack_trace()
in your filter program.

See the documentation, section `Runtime Errors', for the detailed
description and examples.

* connect handler

Connect handler is implemented.

* envfrom and envrcpt

Both handlers take an additional second argument, containing the rest
of the SMTP command line.

* New functions

- string db_name(string fmt)

Return full file name of the database file corresponding to format
`fmt'

- number db_expire_interval(string fmt)

Return the expiration period for db format `fmt'

- string getmx(string domain [, number resolve])

Returns a whitespace-separated list of MX names (if `resolve' is not
given or is 0) or MX IP addresses (if `resolve'==1) for `domain'.  If
`domain' has no MX records, empty string is returned.  If the DNS
query fails, `getmx' raises an appropriate exception.

This interface differs from that of version 3.1.4 in that the calls to
getmx(domain) and getmx(domain,1) can return different number of
entries (see the docs for an example).

* #pragma regex stack

The `#pragma regex' statement can keep a stack of regex flags.  The
stack is maintained using `push' and `pop' commands.  The statement

   #pragma regex push [options]

saves current regex flags on stack and then optionally modifies them
as requested by options.

The statement

   #pragma regex pop [options]

does the opposite: restores the current regex flags from the top of
stack and applies [options] to it.

This statement is useful in include files to avoid disturbing user
regex settings.  E.g.:

   #pragma regex push +extended +icase
    .
    .
    .
   #pragma regex pop

* Optional arguments in user-defined functions

User-defined functions can take optional arguments.  In a declaration,
optional arguments are separated from the mandatory ones by a
semicolon.  For example:

    func foo(number a, number b; string c)

This function is declared with two mandatory arguments (a and b), and
an optional one (c).  Subsequently it can be invoked either as

   foo(x, y, z)      

or

   foo(x, y)

When invoking such functions, any missing arguments are replaced with
default values:

 - 0   for numeric arguments
 - ""  for string arguments

Thus, continuing our previous example, the invocation `foo(x, y)' is
equivalent to `foo(x, y, "")'.

* New statement #include_once

This statement works exactly like `#include' except that it keeps
track of the included files. If the requested file has already been
included, `#include_once' returns silently, while `#include' issues
an error message.

* New statement #require

Requires use of the named module, e.g.:

#require dns

See the documentation, section `Modules', for the description of MFL
module system.

* Internet address manipulation functions

- number ntohl (number N)
- number htonl (number N)
- number ntohs (number N)
- number htons (number N)
- number inet_aton (string S)
- string inet_ntoa (number N)
- number len_to_netmask (number N)
- number netmask_to_len (number N)

* DNS functions

DNS functions are reimplemented in two layers:

1. Primitive calls:

- string primitive_hostname (string IP)
- string primitive_resolve (string S [, string DOMAIN])
- number primitive_hasmx (string DOMAIN)
- number primitive_ismx (string DOMAIN, string IP)

These functions throw an exception if the requested lookup operation
fails.

2. Traditional calls:

- string hostname (string IP)
- string resolve (string S [, string DOMAIN])
- number hasmx (string DOMAIN)
- number ismx (string DOMAIN, string IP)

These are implemented in MFL and work exactly as their predecessors in
3.1.x branch.

To use the traditional calls, add the following statement at the
beginning of your script file:

  #require dns

(see the documentatio, section `Modules' for the description of
#require statement)

* Function `match_cidr'

This function has been reimplemented in MFL.  To use it, add
`#require match_cidr' at the top of your script source (see the
documentatio, section `Modules' for the description of
#require statement)

* Catch arguments

Catch takes two positional arguments: $1 gives the exception code,
$2 is the diagnostic string, explaining what happened in detail.

* New statement `throw'

The `throw' statement throws the given exception.  For example:

    throw invcidr "invalid CIDR (%cidr)"

* New command line option -v (--variable) allows to alter initial value of a
global variable, e.g:

  mailfromd -v ehlo_domain=mydomain.org

The old way of assigning values to the globals from the command line
(by prefixing an assignment with a percent sign) is discontinued.

* Pragmatic options `mailfrom' and `ehlo'

Both options create ambiguities in the language and are therefore
deprecated.  They are still understood but a deprecation warning is
issued when the parser sees them.  To update your scripts:

Change
  #pragma option mailfrom @var{value}
to   
  set mailfrom_address @var{value}

Change  
  #pragma option ehlo @var{value}
to  
  set ehlo_domain @var{value}

* Code generation redone to decrease memory requirements and make compiled
code self-sufficient.

* New statement `const' defines a named constant, e.g.:

  const n 10
  const s "String"

  if $f != s
     ...
  fi

In program text, constants are referred to by their name. In strings,
they are referred to using variable syntax (e.g. "%s").

* It is allowed to initialize variables in declarations.

For example, instead of

    number x
    set x 1

you can write

    number x 1

* Built-in macro __statedir__

New built-in macro `__statedir__' expands to the name of the default
program state directory.

* Changing state directory at run-time

It is possible using `--state-directory' command line option or
`#pragma option state-directory' statement.

* Bugfixes
** Fix incorrect packet length calculation in connect Milter handler.
The bug manifested itself with the following log messages:

- In mailfromd log:

   MailfromFilter: shan_connect: wrong length

- In Sendmail log:

   milter_read(mailfrom): cmd read returned 0, expecting 5
   Milter(mailfrom): to error state
   
** Fix coredumps on printing void returns with --dump-tree
** Fix coredumps on optimizing conditionals like

       if 0
	  do_something
       fi    

** Fix function context checks.

Previous versions bailed out on using context-limited built-ins (like `sa' and
`clamav') in functions. It is fixed. The context limit of the built-in
propagates to the function it is used in, that is defining

func sa_wrapper(string url)
do
	if sa(%url, 3)
	   discard
	fi
done

makes function `sa_wrapper' limited for use in `prog eom' only.	

** Fix passing of string handler arguments between handlers, as in
 
        prog helo
       do
 	  set x $1
        done
 
        prog envfrom
        do
 	  if %x = "dom.ain"
 	  ...	
 
(from 3.1.3)

** If, during sender verification, the remote server replies with
4xx to MAIL FROM command, do not try next sender address, but tempfail
immediately.
           

Version 3.1.90, 2006-12-13

* `==' can be used as well as `=' to test for equality

This is a bit of syntactic sugar for seasoned C programmers, who seem
to type == instinctively (like the author does).

* resolve takes an optional second argument

The argument specifies the domain.  For example, the following calls
are equivalent:

  resolve("puszcza", "gnu.org.ua")        = resolve("puszcza.gnu.org.ua")
  resolve("22.0.120.213", "in-addr.arpa") = hostname("213.130.0.22")  

* listens takes an optional second argument

The second argument specifies the port to use instead of the default 25.

* New functions

- message_header_decode(string TEXT, [string CS])

The TEXT must be encoded as per RFC 2047.  The function decodes it and
returns the resulting string.  Optional argument CS specifies the
character set for the output string.  Default is UTF-8.

- message_header_encode(string TEXT, [string ENC, string CS])

Encodes TEXT according to RFC 2047.  Optional arguments:

 ARG       Meaning          Default value
------+------------------+------------------- 
 ENC       Encoding         quoted-printable
 CS        Character set    UTF-8

Valid values for ENC are quoted-printable, Q, base64, B 

- unfold (string TEXT)

Unfold TEXT as defined in RFC 2822, section 2.2.3.  Return unfolded
string.

* Default logging facility is LOG_MAIL

* While checking sender validity, issue RSET if the previous MAIL
FROM returned 4xx.

Bugfixes:

* `Make install' creates state directory if it does not exist
* `clamav' function could cause coredumps when using socket ports.
* `resolve' function altered its argument if it was a CNAME.
* A typo in gram.y prevented some correct `matches' conditions from
being compiled. In particular, strip_domain_part.mf triggered this
error.


Version 3.1, 2006-12-07 

* Incompatible changes.

For detailed instructions on how to upgrade from version 3.0, please
see http://mailfromd.software.gnu.org.ua/upgrade.html

1. The package refuses to compile without DBM

2. The command line option --config-file (-c) is no longer supported.
To use an alternative filter script, give its name as an argument in the
command line, e.g.

   mailfromd my-script.rc

For backward compatibility, the invocation
`mailfromd --config-file my-script.rc' still works but produces a
warning message.

The semantics of `-c' will change in the next release.
   
3. The function `dbmap' takes an optional third argument.  If it is 1,
then the length of the lookup key will include the terminating null character.

In previous versions dbmap always counted the terminating null
character in the key length.  So, you should add the non-zero third argument
to the calls to dbmap to preserve their functionality.

4. Variables, implicitly declared within a function, are automatic.
Previous versions created them as global.

* Language changes

** Hex and octal constants

Usual C notation (0xNNN for hex and 0NNN for octal) is accepted.

** Bitwise operators: &, |, ^ (logical and, or, xor) and ~ (twos-complement)

** Search path for include files

The `#include' statement handles its argument the same way C
preprocessor does:  the argument is searched in the include file path,
if enclosed in angle brackets (<>), and in the current working
directory first and then in the include file path, if it is enclosed
in double quotes.  The default include file path is

/usr/share/mailfromd/include:/usr/local/share/mailfromd/include

plus $prefix/share/mailfromd/include if $prefix is not `/usr' or
`/usr/local'.

The command line option -I (--include) adds the named directory in
front of the default include path.

** Code optimization

Parse tree is optimized before code generation.  This can be
controlled using -Olevel option, where `level' is the optimization
level.  Currently implemented levels are 0 (no optimization) and 1
(full optimization), which is the default. 

** All variables are now strongly typed.

The declaration of the variable has the form: `TYPE NAME', where TYPE
is one of `string' or `number', and NAME is the variable name.  For
compatibility with the previous versions, the declaration is
optional.  If it is absent, the first assignment to the variable
defines its type.  Subsequent assignments will implicitly cast the
value being assigned to the type of the variable.

** New style of function declarations.  Named parameters.

Functions should be defined as:

func NAME (PARAM-LIST) returns TYPE

where TYPE is as described in the previous paragraph and PARAM-LIST is
a comma-separated list of parameter declarations in the form TYPE
NAME.  Consequently, instead of the positional notation, parameters
can be referenced by their names:

func sum(number a, number b) returns number
do
	return %a + %b
done

Within the function body, the named parameters can be handled the same
way as other variables, in particular they can be assigned new values
using `set' instruction.

For compatibility with the previous version, old type of function
declarations is supported as well.

** Automatic variables

Automatic variables are defined within a function or handler.  Their
scope of visibility ends with the terminating `done' statement.
Automatic variables are declared and referenced the same way as global
ones.  To declare an automatic variable, use `TYPE NAME' notation.
Variable declarations can be intermixed with executable statements.

The following example defines two automatic variables for
the function `foo':

func foo()
do
	number a
	string s
	...

If a variable is declared implicitly within a function or handler, it
is declared automatic.
	
See the documentation for the detailed description and examples.

** New functions:

*** I/O functions: open, close, write, getline
    See http://mailfromd.software.gnu.org.ua/manual/bi/io.html
    
*** Time functions: time, strftime
    See http://mailfromd.software.gnu.org.ua/manual/bi/system.html
    
*** System functions: system
    See http://mailfromd.software.gnu.org.ua/manual/bi/system.html
    
*** DBM functions: dbput, dbdel
    See http://mailfromd.software.gnu.org.ua/manual/bi/db.html

*** String functions: substr, index, rindex
    See http://mailfromd.software.gnu.org.ua/manual/bi/string.html

*** Debugging functions: debug, cancel_debug, program_trace,
    cancel_program_trace
    See http://mailfromd.software.gnu.org.ua/manual/bi/debug.html

*** Mail sending functions: send_mail, send_text, send_dsn
    See http://mailfromd.software.gnu.org.ua/manual/bi/mail.html

** The legacy function numrcpt() has been withdrawn

Use %rcpt_count instead.

** Built-in macros

Built-in macros have names beginning and ending with double underscore.
As their name implies, the macros are expanded to constant values.
The following built-in macros are defined:

1. __file__ expands to the name of the current source file
2. __line__ expands to the number of line in the current source file
3. __function__ expands to the name of the current lexical context,
i.e. the function or handler name.
4. __package__ expands to the string containing package name ("mailfromd")
5. __version__ expands to the textual representation of the program
version (e.g. "3.0.90")
6. __major__ expands to the major version number
7. __minor__ expands to the minor version number
8. __patch__ expands to the version patch level, or 0 if it is not defined.

Built-in macros can be used in variable context.  For example, to use
them within a string or here-document, prepend them with % as if they
were regular variables, e.g.:

   echo "%__file__:%__line__: Checkpoint"

* The envfrom and envrcpt handlers print entire argument array in the
debugging output. 

* New DNS caching scheme.

All DNS lookups are cached on global basis, as opposed to the per-session
basis in previous versions.  The cache is stored in the DBM database
`dns'.  It can be listed and otherwise operated upon using usual
mailfromd commands.

If a lookup gives a positive result, the TTL from the DNS record is
used as the record expiration interval.  For negative lookups, the
default interval of 3600 seconds is used.  It can be altered by the
following pragmatic comment:

  #pragma database dns negative-expire-interval N

* New command line option --xref

Produces a cross-reference listing of global variables.

* Fuller SMTP timeout control

In order to more fully control SMTP transactions, new timeout value
is introduced: initial-response-timeout.  This is the maximum time
to wait for the remote to issue the initial SMTP response.  This value
is especially useful for dealing with the servers that impose a
delay before the initial reply (most notably "CommuniGate Pro"
ones").  The default value is 30 seconds which should be enough for
most normal servers.  See the documentation, node "SMTP Timeouts" for
the detailed discussion.

* No more `retry' options.

The `retry' options and pragmas have been removed.  The new timeout
control scheme warrants that the polling will take at most the given
interval of time.  In particular, that affects:

** Command line option `--retry' 
** Pragma options io-retry and connect-retry

* Bugfixes
** Switch statements without the default branch produced incorrect code
(the very first branch was used as the default one).  This is fixed.
** Fix handling of escape sequences at the beginning of a string and before
the beginning of an interpreted sequence within the string.
** Fix the declarations of the built-in functions `toupper' and `tolower'.
** Fix storing the macro values obtained from Sendmail
** Collect zombie subprocesses as soon as possible
** Fix arithmetical expression syntax in rc.mailfromd
** Fix multiple from address handling
** Fix race condition when using GDBM
  

Version 3.0, 2006-11-05

* The mailfromd binary is now installed in ${prefix}/sbin.  Please,
update your scripts.  You are encouraged to update the startup script
(run `cp etc/rc.mailfromd /wherever-your-startup-lives'), since the new
version contains lots of enhancements (see below).

* The package no longer uses libmilter.

* Several `from' addresses can be specified both with polling functions
and in `#pragma option mailfrom' statement.  In this case the probing
will try each address until either the remote party accepts it or the
list of addresses is exhausted, whichever happens first.  This can
help if a remote host is picky about sender addresses. 

* After discussions with Jan, the final part of the standard poll method
has been redone.  Now the last-resort poll (i.e. querying the domain part
of the sender email, treated as an MX) is done only if the domain has
no MX records.

* New option --dump-macros shows all Sendmail macros used in the
configuration file, by milter states.  It is useful to create Sendmail
`Milter.macros.*' (confMILTER_MACROS_*) statements.

* rc.mailfromd stript two new options:

- rc.mailfromd configtest [FILE]

Checks configuration file syntax.  If FILE is not given, the default
one is assumed.

- rc.mailfromd macros [-c] [FILE]

Generate milter export statements for Sendmail configuration files.
Optional FILE specifies alternative mailfromd configuration file.
By default, `.mc' statements are generated.  Specifying `-c' option
instructs the script to create `.cf' statements instead.

* New pragmatic options `connect-retry' and `connect-timeout' set retry
count and timeout values for initial connections.  The corresponding values 
for I/O operations are set using `io-retry' and `io-timeout' options.
The pragmatic options `retry' and `timeout' are retained for backward
compatibility.  They are synonymous to their `io-' counterparts.  The
default values are:

#pragma option connect-retry 1
#pragma option connect-timeout 30
#pragma option io-retry 3
#pragma option io-timeout 3

* New function `sa' checks the message for spam via SpamAssasin spamd
interface.  It supplies additional data via the global variables
sa_score, sa_threshold, and sa_keywords.

* New function `clamav' checks the message for viruses via ClamAV daemon
interface.  Additional data (the virus name, if found) is stored in
the global variable clamav_virus_name.

* New function `ismx' returns true if the IP address or hostname given by its
second argument is one of the MX records of the domain name given by
the first argument.
 
* New variables `last_poll_host', `last_poll_send', `last_poll_recv' contain
the host name of the lastly polled host, the command sent and the
first line of the reply received.  The variables are set by polling
functions. 

* New variable `cache_used' is set to true if cache data were used instead of
polling, and to false otherwise.  The variable is set by stdpoll and
strictpoll built-in functions (and by `on poll' statement, accordingly).

* New string functions: `length' and `substring'

* Here document syntax expanded.

** Removing leading whitespace

Inserting a single space between the dash and the terminator word in
the beginning of the here-document construct, as in:

<<- WORD
...
WORD

instructs parser to remove leading white space characters
from each line of the document body, including terminating WORD.

** Expansion of macros and variables

Variables and sendmail macros are expanded when used within a
double-quoted string or a here-document body.  The variable expansion
and backslash interpretation is suppressed by quoting the WORD, e.g.:

<<\WORD
...
WORD

or

<<'WORD'
...
WORD

** Numeric escape sequences

Two new kinds of escape sequences are supported:

 \0ooo, where o is any octal digit
 \xhh, where h is any hex digit

** Back-references.

References to the parenthesized subexpressions of the previous regular
expression are expanded both in the code and in double-quoted string
literals.  For example:

 if domainpart $f matches '\(.*\).com'
   set d \1
 fi  

* Bugfixes
** Fix berkeley 4.x support
** Fix expiration of the greylist and rate databases.
** Fix returning multiline replies.  The last line of the reply was not taken
into account unless it ended with a newline. 
** Fix type casting of arguments to user-defined functions
** Fix argument passing in function calls generated for `on poll' statements.


Version 2.0

* Program requires Mailutils version 1.0 or newer
* Support for old DBM and NDBM has been withdrawn.
* Added support for Berkeley DB versions 3.x and 4.x

* INCOMPATIBLE CHANGES

** To use version 1.x configuration files, the following changes should
be applied to them:

 1. The entire code section should be enclosed in the following
    statement:

    prog envfrom
    do
	...
    done

    See the section `Handler declarations' below for the detailed
    description.
 2. Convert any `rate' statements to function calls, e.g.:

        if rate $f 180 / minute

    should be rewritten as

        if rate($f, interval(minute)) > 180

    See the section `rate(key, interval)' below for the detailed description.
    See also section "Special test functions" in the mailfromd documentation.

** Format of cache and rates database has changed: the key field now
includes the trailing nul character, which is also reflected in its
length.  This allows for empty (zero-length) keys.  To convert existing
databases to the new format, run 

   mailfromd --compact --all

after compiling the package.

** The database management options (--list,--delete,--expire) do not take
any argument.  To specify that the option refers to the rate database,
use --format=rate option.

* Language features

** Compiled code

Configuration file handling completely rewritten.  The file is parsed
into a pseudo-code program, which is executed considerably faster than
the parse tree in 1.x branch.

** Sendmail macros

Multiletter Sendmail macros can be used with and without
surrounding curly braces, i.e. ${rcpt_count} and $rcpt_count are both
valid. 

** File inclusion

Configuration file can include other files.  The syntax is:

#include "FILENAME"

Inclusion depth is not limited.

** Adjacent expressions concatenate:

  $f => "gray@gnu.org.ua"
  ${client_addr} => "127.0.0.1"

  $f "-" $client_addr => "gray@gnu.org.ua-127.0.0.1"

** Arithmetical expressions

The four usual arithmetical expressions are now supported.

** Comparisons

In addition to equal (=) and not equal (!=) the following comparison
operators are supported: <, <=, >, >=.  Their precedence and
associativity is the same as in C.

** Type casting

The rules for implicit type casts are:

  1. Both arguments to an arithmetical operation are cast to numeric
     types.
  2. All arguments of the concatenation operation are cast to string
     type. 
  3. Both arguments to `match' or `fnmatch' function are cast to
     string type.
  4. The argument of the unary negation (arithmetical or boolean) is
     cast to numeric type.
  5. Otherwise, if the arguments to a binary operation have different
     types, the right-hand side argument is cast to the type of the
     left-hand side argument.

There is no special syntactic sugar for explicit type casting.  To
cast an expression to string, concatenate an empty string to it:

  %var ""

To cast an expression to numeric, add it to zero:

  %var + 0

** Single-quoted strings

In addition to double-quoted strings, single-quoted ones are also
supported.  The single-quoted strings are not subject to backslash
expansion, thus they are particularly useful for writing regular
expressions: 

  if $f matches '.*\.com'

** Splitting strings between several lines.

Double-quoted strings can be split over several lines, by placing
a backslash immediately before the newline.  For example:

"A very\
 long string"

produces "A very long string". 
  
** Here document syntax and multiline sendmail replies

Mailfromd supports "here document" syntax:

<<[-]WORD
...
WORD

Optional '-' instructs parser to remove leading tabulation characters
from each line of the document body, including terminating WORD.  This
allows for here documents to follow normal program indentation. The
backslash expansion is performed on the contents of the here document,
unless WORD is quoted (i.e. either 'WORD' or \WORD).

This is particularly useful in providing multiline Sendmail replies:

  reject 550 5.0.0 <<-EOT
	 This service is not available now.
	 Please, refer to http://some.site for more information
	 on the subject.
	 EOT	 

** Handler declarations

The program consists of a set of handler declarations.  Each handler
is defined as

    prog STATE
    do
       ...
    done

where `...' represents the actual code, and STATE is the milter state
this handler is defined for. Recognized milter states are: helo,
envfrom, envrcpt, header, eoh, body, eom.

** Positional arguments ($N notation)

Handlers can take several positional arguments, which can be
dereferenced in the program using $N notation, where N is a decimal
number.  The semantics of the positional arguments depends on the state
for which the handler is designed.  For example:

    prog helo
    do
	/* For helo, $1 means helo domain */
	if $1 matches "gnu.org.ua"
	   ...
	fi
    done   

** Internal variables (% notation)

Mailfromd variables can be defined using `set' statement:

  set VAR expr

where VAR is the variable name.  The variables are dereferenced using
%VAR notation.  Their values are retained between handlers, for
example:

    prog helo
    do
	set helo_domain $1
    done

    prog envfrom
    do
	if $f = "gray" and %helo_domain matches "gnu.org.ua"
	   ...
	fi
    done 

The `set' statement can be used both inside and outside of program
handlers or functions.  When used outside them, it declares a global
variable and assigns it an initial value.  The variable will be
initialized to that value at the beginning of each message.
    
** Built-in function syntax

Built-in functions of more than 1 argument are invoked using the usual
C-like syntax, e.g.:

    name(arg1, arg2, arg3)

Built-in functions of one argument can be invoked with or without
parentheses:

    name arg
    name(arg)

** User defined functions

User defined functions are declared using the following syntax:

func NAME ( TYPELIST ) returns TYPE
do
	...
done

where NAME is the name of the function, TYPELIST is a comma-separated
list of parameter types, and TYPE is the return type of the
function. Types are designated by a single letter: 'n' denotes the numeric
type, 's' denotes the string type.

Within the function body, the arguments are denoted using positional
argument notation (see `Positional arguments' above).  The `return'
statement is used to return a value from the function.  For example:

func sum(n,n) returns n
do
	return $1 + $2;
done

** Switch statement

The mailfromd language now has switch statement.  Its syntax is
similar to that of C:

switch EXPR
do
   case VAL [or VAL...] :
	STMT
	.
	.
	.
   default:
	STMT		
done   

where EXPR is any valid mailfromd expression, VAL is a literal value
(numeric or string), STMT is any mailfromd statement or a list of
statements.  For example:

switch %x
do
	case 1 or 2:
	     echo "Accepting mail"
	     accept

	default:
	     reject
done

** Catch statement

The new `catch' statement can be used to handle exceptional conditions
occurring within a function.  An exceptional condition is signalled
when the filter script program encounters a condition it is not able
to handle.  See the documentation, section "Exceptions" for the
details.

The syntax of the `catch' statement is:

catch EXCEPTION-LIST
do
   HANDLER-BODY
done

where EXCEPTION-LIST is the list of exception types, separated by the
word `or'.  Special form `catch *' catches all exceptions.

The HANDLER-BODY is the list of statements comprising the handler body.

** On statement

The support for `on' statement has been entirely rewritten.  The
statement is implemented as a wrapper around `catch'.  Instead of
`poll' you can specify any function call as its selector value.

For example, this statement:

prog envfrom
do
        on poll $f do
        when success:
            accept
        when not_found or failure:
            reject 550 5.1.0 "Sender validity not confirmed"
        when temp_failure:
            tempfail 450 4.1.0 "Try again later"
        done
done

is actually a shortcut for:

function poll_wrapper(s) returns n
do
        catch &success or &not_found or &failure or &temp_failure
        do
              return $1
        done
        return stdpoll($1, %ehlo_domain, %mailfrom_address)
done

prog envfrom
do
        switch poll_wrapper($f)
        do
        case &success:
            accept
        case &not_found or &failure:
            reject 550 5.1.0 "Sender validity not confirmed"
        case &temp_failure:
            tempfail 450 4.1.0 "Try again later"
        done
done

(See also the description of %ehlo_domain and %mailfrom_address variables)

** MX matching

The `matches' and `fnmatches' operations has been extended to allow
operations on MX lists.  The test

   if ${client_addr} mx matches '.*\.gnu\.org'

yields true if the list of MXs for the IP address ${client_addr}
contains a host name that matches the regular expression
'.*\.gnu\.org'.  The left side argument can be either a hostname or IP
address or an RFC 2822 email address.  In the latter case, its domain
part is used to query for the MX records.

The similar 'mx fnmatches' construction is also available.

Both `mx' tests can throw one of the following exceptions: not_found,
failure, temp_failure.

** #pragma database

New pragma `database' controls various aspects of databases used by
the program.  The pragma has four forms:

1. Store the database DBNAME in the given FILENAME

   #pragma database DBNAME file FILENAME

2. Set the expiration interval for DBNAME:
   
   #pragma database DBNAME expire-interval INTERVAL

   INTERVAL can be any valid interval specification (see the next 
   section).

If DBNAME is "cache", two additional forms are understood:
   
3. Set the expiration period for positive cache records:

   #pragma database cache positive-expire-interval INTERVAL

4. Set the expiration period for negative cache records:

   #pragma database cache negative-expire-interval INTERVAL

The forms 3. and 4. are equivalent to

   #pragma option positive-expire-interval INTERVAL
and
   #pragma option negative-expire-interval INTERVAL

correspondingly.           

** Time interval specification

  Time intervals can be specified as an English text, e.g. "1 hour 35
minutes".  The following pragmas take a time interval specification as their
argument:

#pragma option timeout
#pragma option milter-timeout
#pragma option expire-interval
#pragma option negative-expire-interval
#pragma option positive-expire-interval
#pragma option rates-expire-interval
#pragma option lock-retry-timeout

* New built-in functions:

** dbmap(dbname, key)

Returns true if `key' is found in the database file `dbname', E.g.:

   dbmap("/etc/mail/aliases.db", $f)
   
** domainpart(str)

Returns the domain part of `str' if it is a valid email address,
otherwise returns `str' itself. 

** greylist(key, interval)

Returns true if the `key' is found in the greylist database
(controlled by `#pragma database greylist' pragma).  The argument
`interval' gives the greylisting interval in seconds.  The function
sets internal variable %greylist_seconds_left to the number of seconds
left to the end of greylisting period.  Sample usage:

 set gltime 500
 if greylist(${client_addr} "-" $f "-" ${rcpt_addr}, %gltime)
   if %greylist_seconds_left = %gltime
      tempfail 470 "You are greylisted for " %gltime " seconds"
   else   
      tempfail 470 "Still greylisted for " %greylist_seconds_left "seconds"
   fi
 fi		     

** hasmx(host)

Returns true if `host' has any MX records.  The function can throw one
of the following exceptions: not_found, failure, temp_failure.

** interval(string)

Converts its argument, which should be a valid time interval
specification, to seconds

** localpart(str)

Returns the local part of `str' if it is a valid email address,
otherwise returns unchanged `str'. 

** match_cidr(ip, cidr)

Returns true if the IP address `ip' matches the network block `cidr'.
For example:

  match_cidr(${client_addr}, "213.130.0.0/19")

Possible exceptions: invip, if the first parameter is not a valid IP,
and invcidr if the second parameter is not a valid CIDR.
  
** stdpoll(email, domain, mailfrom)

Performs standard poll for `email', using `domain' as EHLO domain and
`mailfrom' as MAIL FROM: address.  Returns 0 or 1 depending on the
result of the test.  Can raise one of the following exceptions:
failure, temp_failure.

In `on' statement context, it is synonymous to `poll' 
without explicit `host'. 

** strictpoll(email, domain, mailfrom, host)

Performs strict poll for `email' on host `host'.  See the description
of stdpoll for the detailed information.

In `on' statement context, it is synonymous to `poll host'. 

** _pollhost(ip, email, domain, mailfrom)

Poll SMTP host `ip' for email address `email', using `domain' as EHLO
domain and `mailfrom' as MAIL FROM: address.  Returns 0 or 1 depending
on the result of the test.  In contrast to strictpoll function, this
function does not use cache database and does not fall back to MX poll
if the poll tempfails.  The function can throw one of the following
exceptions: failure, temp_failure.

** _pollmx(domain, email, domain, mailfrom)

Poll MX-s of the `domain' for email address `email', using `domain' as EHLO
domain and `mailfrom' as MAIL FROM: address.  Returns 0 or 1 depending
on the result of the test.  In contrast to stdpoll function, _pollmx
function does not use cache database and does not fall back to host poll
if the poll fails.  The function can throw one of the following
exceptions: failure, temp_failure.

** tolower(string)

Returns a copy of the string str, with all the upper-case characters
in string translated to their corresponding lower-case counterparts.
Non-alphabetic characters are left unchanged.

** toupper(string)

Returns a copy of the string str, with all the lower-case characters
in string translated to their corresponding upper-case counterparts.
Non-alphabetic characters are left unchanged.

** rate(key, interval)

Returns the mail sending rate for `key' per `interval'.  This function
replaces `rate' statement from 1.x branch.  To convert old rate
statements use the following algorithm:

Old statement: if rate KEY LIMIT '/' EXPR
New statement: if rate(KEY, interval("EXPR")) > LIMIT

For example:

Old statement: rate $f 180 / 1 hour 25 minutes
New statement: if rate($f, interval("1 hour 25 minutes")) > 180

** resolve(host)

Returns the IP address corresponding to `host' or "0" if it cannot be
resolved.

** validuser(user)

Returns true if `user' is a valid local account.  It uses mailutils
authentication mechanisms.

* Global variables

** %ehlo_domain

Name of the domain used by polling functions in EHLO or HELO command.
It is set by `#pragma option ehlo' directive, or via --ehlo command
line option.  

** %mailfrom_address

Email address used by polling functions in 'MAIL FROM' command.  Set
by `#pragma option mailfrom' directive or via --mailfrom command line
option. 

** %rcpt_count

The variable %rcpt_count keeps the number of recipients given so far.
The variable is defined in the envrcpt state. 

* Database expiration

The operation of `mailfromd --expire' has been completely redesigned
to avoid skipping some keys when using GDBM.

* Database compaction

New option --compact starts "database compaction" process,
which removes all expired entries and empty blocks from the database. 
It also converts any obsolete (not nul-terminated) keys to
nul-terminated ones.  During this process the original database file is
locked for writing, so the running mailfromd instance is able to read
entries from it, but cannot write or update it.

The existed database will be replaced with the compacted version only
if there were no errors during the process.  If you wish to ignore any
failed reads (keys that were not retrieved), use the 
--ignore-failed-reads option. 

* Database locking

Before accessing, any database file is locked using kernel locking.
By default, if the first attempt to lock the file fails, two more
attempts are undertaken in 1 second intervals.  If the lock cannot be
acquired after the last attempt, the database file is opened in read-
only mode.  The number of locking attempt and the timeout value are
controlled by command line options --lock-retry-count and
--lock-retry-timeout, or the corresponding pragmas:

#pragma option lock-retry-count
#pragma option lock-retry-timeout

* Selecting the database format and file

** New option -H (--format) specifies which format is the database being
operated upon by any of the database management options.  Recognized
formats are:

  cache        Poll cache database
  rate         Sending rate database
  greylist     Greylisting database (see below)

** New option --all can be used with one of the options --expire or
--compact to apply the operation to all configured databases.  This is
useful to invoke mailfromd as a crontab job.
  
** New option --file allows to explicitely specify the database file name.
Notice, that in contrast to the previous version, the name should
include the suffix.

* Debugging

** New option --lint (-l, --syntax-check): check the configuration file
syntax.  

** The argument to --debug option should be the numeric debug level.  The use 
of characters 'c', 'd', 'l', 'y' is discouraged (although still
supported for a while).  See below for the alternatives.

** New option --dump-code dumps the listing of the assembled code on screen
(similar to the earlier --debug=c)

** New option --dump-tree dumps the parse tree in human-readable form
(earlier --debug=d option)

** New option --dump-grammar-trace prints grammar parser traces while parsing
the configuration file (earlier --debug=g option).

** New option --dump-lex-trace dumps lexical analizer traces
(earlier --debug=l option).

** New option -L (--log-tag) sets the identifier used in syslog messages.

** New option --source-info includes source line information into the
debugging messages.  Previously this information was included by default.

* New option --group (-g) allows to retain the given supplementary group when
switching to user privileges.  By default mailfromd does not retain
any supplementary groups.  The use of this option may be necessary if
your mailfromd script needs to access some databases that have
restrictive access privileges.  For example, if mailfromd runs with
the privileges of user 'mail' (the default) and needs to access
/etc/mail/aliases.db, which is usually owned by root.smmsp and has
access rights 0640, you should run

         mailfromd --group smmsp

* New option --source (-S) sets the source address mailfromd will use for
any TCP connections.  The configuration file equivalent is

         #pragma option source

* To set up the local account validation (see the description of `validuser'
function above) mailfromd uses authentication options from mailutils.
See the mailutils documentation, chapter `Authorization and Authentication
Principles' for the detailed description of these. 	 

* Code generation optimized to avoid unnecessary instructions and to reduce
code size.

* MX lookups no longer recurse to parent domains.  Previously, if
the domain "some.domain.com" had no MX records, mailfromd would lookup for
MXs of "domain.com" and use these instead.  This is no longer the
case.  

* Added testsuite


Version 1.4

* Configuration

Added possibility to link against the forked version of libmilter
(--with-forks). The patch for sendmail-8.13.1 is included
(etc/sendmail-8.13.1.diff).

* Configuration file

** New unary expression `listens' checks if the host listens on port 25.
** Several `#pragma option relay' statements accumulate

* Bugfixes

** Fixed coredump on incorrect libmilter socket specification.
** Fixed `poll for EMAIL as EMAIL'.


Version 1.3

* Rewritten DNS resolver functions in order to take into account CNAMEs.
* Updated Makefiles to allow for compilation with the CVS Mailutils
* Improved documentation.


Version 1.2

* Implemented sending rate control.

This feature allows to impose a limit on the number of messages a
user can send within a given interval. If this number is exceeded, the
connection is refused until enough time passes to keep the rate within
the given limit.


Version 1.1

Mostly bugfixes.

Version 1.0

Lots of major improvements. Implemented two methods of sender address
verification, controlled by a sophisticated configuration file. Sender
domains and emails can also be distinguished basing on POSIX regex or
shell-style globbing patterns.


Version 0.2

First release.


=========================================================================
Copyright information:

Copyright (C) 2005-2025 Sergey Poznyakoff

   Permission is granted to anyone to make or distribute verbatim copies
   of this document as received, in any medium, provided that the
   copyright notice and this permission notice are preserved,
   thus giving the recipient permission to redistribute in turn.

   Permission is granted to distribute modified versions
   of this document, or of portions of it,
   under the above conditions, provided also that they
   carry prominent notices stating who last changed them.

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