- update to 2.7.0 With a synergy of four solutions, using amavisd-new
in a pre-queue filtering setup became a sensible / better behaved solution:
- old helper programs amavis.c and amavis-milter.c are no longer distributed
with the package, along with the whole helper-progs subdirectory.
As a milter client please use the more modern 'amavisd-milter' package by
Petr Rehor, available at http://sourceforge.net/projects/amavisd-milter/
- the "smtpd_proxy_options=speed_adjust" Postfix option, available since
Postfix 2.7.0 (20091101), improves decoupling between SMTP clients
and a content filter in a proxy setup, reducing the number of content
filtering processes needed for the same mail load. With this option
turned on, a Postfix SMTP server receives the entire message before
connecting to a before-queue content filter;

- a master_deadline option and its API equivalent, available in SpamAssassin
since version 3.3.0, allows for time limiting on lengthy rules checking,
while still providing results when a time limit is exceeded; this makes
it more suitable for time-sensitive setups like a pre-queue filtering setup;

- reworked sub-task time limiting in amavisd, along with its counterpart
solution in SpamAssassin, makes it better suited to a real-time nature
of pre-queue filtering setups, where one has no control over how long
SMTP clients are willing to wait at the data-end stage;

- a re-purposed command line option 'reload' now does a warm restart,
keeping sockets available to an MTA client at all times, thus reducing
a chance that an MTA would even notice a content filter's warm restart.