valiases mimics the sendmail behavior of evaluating aliases for mail sent to one or more virtual mail addresses. It checks whether any of the (visibly) addressed mail accounts of an email message matches one of the configured aliases, and resends mail to the alias replacement. If you don't have access to /etc/aliases but you need it, this program is for you.
The Moxy Mail Proxy acts as a mail server for multiple domains, transparently proxying mail to different hosts and/or ports. Mail servers transparently receive mail on non-standard ports (i.e., other than 25), users retain complete control over their mail server, mail bandwidth usage is logged on a per destination or per email address basis, mail can be directed to multiple servers/ports simultaneously, and more.
pine2mutt is a simple Perl script interesting to people who switch from using pine to mutt. It converts pine's .addressbook into mutt-readable aliases, enables pine-like sent-mail-folder handling and provides pine-like keybindings by sourcing the file "Pine.rc" which comes with mutt.
sendqmailq is intended for home computers that run qmail as their MTA but do not have permanent connection to the Internet. The outbound emails are stored locally in a queue, and when the IP connection is brought up, sendqmailq sends them to the ISP's SMTP server. Unlike serialmail, sendqmailq sends one single copy of an email to multiple recipients (instead of one copy each).