General-Purpose Mail Filter
The release 7.0 removes the features which were declared as obsolete in 6.0 and introduces important new features, both syntactical, at the MFL level, and operational.
Unless your filter used any deprecated features, it should work correctly after upgrade to this version. It will, however, issue warning messages regarding the deprecated features (e.g. the use of ‘%’ in front of identifiers, as described below). To fix these, follow the upgrade procedure described in upgrade procedure.
The removed features are:
The MFL syntax has changed: it is no longer necessary to use ‘%’ in front of a variable to get its value. To reference a variable, simply use its name, e.g.:
set x var + z
The 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 a string literal remains mandatory.
Another important changes to MFL are user-defined exceptions (see User-defined Exceptions) and the try–catch construct (see try–catch).
Several existing MFL functions have been improved. In
particular, it is worth noticing that the
open function, when
opening a pipe to or from a command, provides a way to control where
the command’s standard error would go (see standard error).
accept function (or action) issues a warning if its use would
cancel any modifications to the message applied by, e.g.,
header_add and similar functions. See Message modification queue, for a detailed discussion of this feature.
The most important change in
mailfromd operation is that
the version 7.0 is able to run several servers (see conf-server).
Dedicated callout servers make it possible to run sender
verifications in background, using a set of long timeouts, as
prescribed by RFC 2822 (see SMTP Timeouts). This diminishes
the number of false positives, allows for coping with servers showing
large delays and also reduces the number of callouts performed for
This release no longer includes the
smap utility. It was
moved into a self-standing project, which by now provides much more
functionality and is way more flexible than this utility was. If you
are interested in using
http://www.gnu.org.ua/software/smap, for a detailed
information, including pointers to file downloads.
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