Only patch if you really need to and only if you understand exactly what the patch does. Contents Introduction How to apply Minimum Patches Glibc Patch by Phil Edwards Bugfix to qmail-Local by Erik Sjoelund 0.0.0.0 as Local Patch by Scott Gifford sendmail -f correction by David Phillips Small Site Patches RFC 2821 Patches by Matthias Andree and Jonathan de Boyne Pollard Any-To-Cname Patch by Jonat