Cyrus2Dovecot is a full-featured command line tool for converting the email messages of one or more users from the Cyrus format to Dovecot Maildir++ folders. It allows you to perform a server transition which is fully transparent to both POP and IMAP users, as virtually all available metadata is preserved during the conversion. This includes message UIDs, INTERNALDATEs, IMAP folder subscriptions, the UIDVALIDITY and UIDNEXT values for each folder, as well as all IMAP flags (including the first 26 user-defined keywords).
postprox is a minimal Postfix SMTP proxy which copies an SMTP conversation between its input and another SMTP server, but spools the DATA portion to a temporary file and runs a specified program on it before passing it on to the output server. It can potentially output an SMTP error code instead of the data if the content filter says to do so.
Anti-Spam Agent for Novell NetMail is a replacement for SpamAssassin's spamd. It will tell the NetMail server to send all new email to it for spam checking. If SpamAssassin determines that the email is spam, you can either have it deleted, or have "X-Spam-Flag: YES" added to the message header. This project also includes assistance for others to write their own NetMail agents.
NewsOutlook is a tool that aims to improve the signal to noise ratio of Usenet newsgroups and syndication feeds (RSS and Atom) by selecting only useful news. It consists of two modules: a Web-based configuration front-end and a server daemon. It uses the HTML::Mason framework and stores data in a MySQL database.