Postfix is written and maintained by Wietse Venema who has also written tcp_wrappers, and Satan. Postfix began its life as VMailer but Wietse has released the software under the IBM GPL and IBM's lawyers discovered that VMailer was too similar to an existing trade mark so the name had to be changed. Postfix is written as a drop in replacement for sendmail and it comes very close to hitting the mark on this. There are a few “gotchas” which can bite you but they are not serious. Wietse actively supports Postfix through the postfix-users mailing list and there is also a developers mailing list. You can subscribe to the postfix-users mailing list this way: echo subscribe postfix-users | mail email@example.com. You can subscribe to the developers list in this way: echo subscribe postfix-testers | mail firstname.lastname@example.org. One last list we should mention is the announce list. You can join the announce list in this way: echo subscribe postfix-announce | mail email@example.com. Postfix development is on-going and these mailing lists are quite active as of this writing. Archives for the mailing lists may be found at: http://www.egroups.com/group/postfix-users/ and at: http://msgs.SecurePoint.com/postfix/.