It’s been a while but the Postfix stable release 2.7.0 is available. For the past releases, the focus has moved towards improving the code and documentation, and updating the system for changing environments. You can read the release notes but the biggest changes are:

  • Improved before-queue content filter performance. With
    “smtpd_proxy_options = speed_adjust”, the Postfix SMTP server
    receives the entire message before it connects to a before-queue
    content filter. Typically, this allows Postfix to handle the same
    mail load with fewer content filter processes.
  • Improved address verification performance. The verify database
    is now persistent by default, and it is automatically cleaned
    periodically, Under overload conditions, the Postfix SMTP server
    no longer waits up to 6 seconds for an address probe to complete.
  • Support for reputation management based on the local SMTP client
    IP address. This is typically implemented with “FILTER transportname:”
    actions in access maps or header/body checks, and mail delivery
    transports in master.cf with unique smtp_bind_address values.
  • The postscreen daemon (a zombie-blocker in front of Postfix) is
    still too rough for a stable release, and will be made “mature”
    in the Postfix 2.8 development cycle (however you can use Postfix
    2.7 with the Postfix 2.8 postscreen and dnsblog executables and
    master.cf configuration; this code has already proven itself).

No functionality has been removed, but it is a good idea to review
the RELEASE_NOTES file for the usual minor incompatibilities or
limitations.

By the way you still need to edit the ‘src/util/sys_defs.h‘ file.

For instructions on how to upgrade Postfix please read Upgrading Postfix.