Postfix is an attempt to provide an alternative to the widely-used Sendmail program. Postfix attempts to be fast, easy to administer, and hopefully secure, while at the same time being sendmail compatible enough to not upset your users.
License: IBM Public License
Changes:
CN comment strings are now null-terminated after sanitization. "Bad address pattern" errors with non-address patterns in namadr_list_match() calls are avoided. A "cleanup -v" panic has been fixed that occurred because the new "SMTP reply" request flag did not have a printable name. Using "Before-queue content filter", RFC3848 information was not added to the headers. A poorly-implemented integer overflow check for TCP MSS calculation had the unexpected effect that people broke Postfix on LP64 systems. Delivery is deferred when a mailbox file is not owned by the recipient.
More...