Postfix stable release 3.4.0

[An on-line version of this announcement will be available at http://www.postfix.org/announcements/postfix-3.4.0.html]

Postfix stable release 3.4.0 is available. This release ends support for legacy release Postfix 3.0.

The main changes are below. See the RELEASE_NOTES file for further details.

You can find the updated Postfix source code at the mirrors listed at http://www.postfix.org/.