Exim-Python is an extension to Exim that adds the ability to execute compiled Python functions and methods from within Exim configuration file string expansions. Since Exim uses string expansions heavily throughout it's operation, this feature allows powerful added control to an already very flexible mail server.
Maverix is an AOLserver module that implements the SMTP protocol and acts as an SMTP proxy with anti-spam and anti-virus capabilities. It includes a Web interface to manage quarantined messages and an administrative interface based on OSSWEB. Supported anti-spam software includes SpamAssassin and DSPAM, and supported anti-virus software packages are ClamAV and Sophos. Features include whitelisting, greylisting, and blacklisting, periodic digests with quarantined messages, a challenge/response mechanism, POP-auth, and short-TTL URLs for digests.
MFilter is a replacement for maildrop/procmail and fetchmail/getmail. It is an email retriever that supports Maildir or command delivery and processing. Its secondary goal is to facilitate the life of the network administrator by centralizing the downloading, filtering, and classification of mail in a simple and flexible way. Some of its features include XML file based configuration and logging of each action taken.
odmrd is a server for the "On Demand Mail-Relay" protocol specified in RFC2465. It can be used as a standalone daemon or in inetd mode. It needs a MySQL server to store authentication and optional accounting information. It also requires a BSMTP-capable mailserver, such as Exim or postfix.
smtpfilter is a filter for an SMTP session which passes the session through transparently in real time, except for the DATA command which is intercepted in order to scan the data for spam and/or viruses with the scanner of your choice. The sources are heavily commented. The default spam filtering is a hybrid approach that uses spamassassin to self-train the excellent spamprobe Bayesian filter which works on a per-site rather than per-user basis. The virus checking can use clamav or NAI, or any other command- line scanner.
Java SMTP Mail Component provides an easy API to send email from an application. The API has option to send emails directly to the recipients mail server without a relaying mail server. Plain authentication is supported for mail server authentication. Mail attachments are supported using MIME.