[An on-line version of this announcement will be available at http://www.postfix.org/announcements/postfix-3.3.0.html]
Postfix stable release 3.3.0 is available. This release ends support for legacy release Postfix 2.11.
The main changes are:
Dual license: in addition to the historical IBM Public License 1.0, Postfix is now also distributed with the more recent Eclipse Public License 2.0. Recipients can choose to take the software under the license of their choice. Those who are more comfortable with the IPL can continue with that license.
The postconf command now warns about unknown parameter names in a Postfix database configuration file. As with other unknown parameter names, these warnings can help to find typos early.
Container support: Postfix 3.3 will run in the foreground with "postfix start-fg". This requires that Postfix multi-instance support is disabled (the default). To collect Postfix syslog information on the container's host, mount the host's /dev/log socket into the container, for example with "docker run -v /dev/log:/dev/log ...other options...", and specify a distinct Postfix syslog_name setting in the container (for example with "postconf syslog_name=the-name-here").
Milter support: applications can now send RET and ENVID parameters in SMFIR_CHGFROM (change envelope sender) requests.
Postfix-generated From: headers with 'full name' information are now formatted as "From: name <address>" by default. Specify "header_from_format = obsolete" to get the earlier form "From: address (name)".
Interoperability: when Postfix IPv6 and IPv4 support are both enabled, the Postfix SMTP client will now relax MX preferences and attempt to schedule similar numbers of IPv4 and IPv6 addresses. This works around mail delivery problems when a destination announces lots of primary MX addresses on IPv6, but is reachable only over IPv4 (or vice versa). The new behavior is controlled with the smtp_balance_mx_inet_protocols parameter.
Compatibility safety net: with compatibility_level < 1, the Postfix SMTP server now warns for mail that would be blocked by the Postfix 2.10 smtpd_relay_restrictions feature, without blocking that mail. There still is a steady trickle of sites that upgrade from an earlier Postfix version.
You can find the updated Postfix source code at the mirrors listed at http://www.postfix.org/.