Unified Qmail Patch

The Unified Qmail Patch is a software solution that offers a comprehensive compilation of various patches for the qmail MTA. It delivers a variety of features that meet the demands of high-end production servers. One of the highlights of the patch is its support SMTP AUTH after STARTTLS, which allows users to encrypt their connections when sending emails.

Another standout feature is Maildir++, which offers more robust email storage capabilities compared to traditional mail spools. The patch also offers support for regexp in badmailfrom, making it easy to filter out unwanted emails.

Unified Qmail Patch offers a range of other features that include external todo support, big remote concurrency patch, oversized dns responses, and reverse dns check, among others. Additionally, there's a tab bug fix to help smooth out any issues with .qmail files and a Linux link sync.

Other patches included in Unified Qmail Patch are the auth-only after TLS patch from Gentoo, Maildir quota fix patch from Gentoo, and the qregex memleak fix patch from Gentoo. The software also features David Phillips' sendmail flagf patch, Russ Nelson's QMTP patch for qmail-remote, and Jay Austad's random qmqp pickup.

Furthermore, this software solution also includes an integer overflow fix in qmail-smtpd.c, added support for SMTP throttling, and checks if the 'mail from' value is different from the username used for SMTP AUTH, which prevents source address spoofing. The 'mail from' verification is now configurable through a knob defined in /var/qmail/control/spoofcheck or in the environment variable $SPOOFCHECK.

Overall, Unified Qmail Patch is an excellent software solution that provides a plethora of patches to the qmail MTA, making it a must-have for those looking for a top-notch email solution.