Wietse Venema anunciaba hoy a la madrugada la release de una nueva versión estable de Postfix, 2.5.0. Las mejoras principales son:

– TLS (SSL) support was streamlined further, and provides a new
security level based on certificate fingerprints instead of CA
signatures. See TLS_README for details.

– Milter support was updated from the Sendmail 8.13 feature set and
now includes most of the features that were introduced with
Sendmail 8.14. See MILTER_README for details.

– Stress-adaptive configuration was introduced. This allows the
Postfix SMTP server to temporarily adjust its rules under conditions
of overload, such as a malware attack or backscatter flood. See
STRESS_README for details.

– The queue manager scheduler was refined. It now provides per-transport
scheduling controls and allows for adjustment of the sensitivity
to mail delivery (non-)errors. See SCHEDULER_README.

– Security was improved by introducing a Postfix-owned data_directory
for storage of randomness, caches and other non-queue data. This
change avoids future security loopholes due to untrusted data
sitting in root-owned files or in root-owned directories. Writes
to legacy files in root-owned directories are automatically
redirected to files in the new data_directory.

Interesante sobre todo el tema de «stress» :-)
Para una descripción más detallada de los cambios: RELEASE_NOTES.