Release Notes: This release cleans up many issues with the previous one and adds a few new features, the most important of which are regular expression (PCRE)-based content filters for both message headers and the message body. There is a new "error" director driver which gives the postmaster control over the error message text for specific rejected addresses. The "pipe" transport now has far more control and flexibility over how it handles abnormal conditions, allowing it to correctly handle temporary errors from the likes of the Cyrus IMAP daemon. Bounce messages are now much more readable.
Release Notes: There have been a great many significant changes since 184.108.40.206. Some of the most significant involve new access control features and much better security against DNS spoofing. One of the more fun new features is a handy little AWK script for reporting interesting statistics from your logfile.
Release Notes: Optional use of TCP Wrappers has been eliminated and all its features have been directly integrated. There are also a number of improvements to the SMTP transport.