Mover is a system designed to move mail while eliminating as much metadata as possible. In fact, it eliminates virtually all metadata, except for the order and possibly the time that a message arrives at a given site. Addresses are encryption keys. The encrypted messages are sent to all mover locations. The intended recipient uses their key to decrypt the message.
openICEM is a highly scalable server software that aims to provide a certified email service as specified by Italian law. It is based around the Postfix MTA, python-ldap, and python-clamd. It makes use of XML-RPC for communication among servers and does not require any shared service or shared filesystem.
S22.Imap is an easy-to-use and well-documented .NET library component for communicating with and receiving electronic mail from an Internet Message Access Protocol (IMAP) servers. It supports IMAP IDLE notifications and IMAP over SSL, allows selective fetching of parts of mail messages, is inherently thread-safe, and is well documented with lots of example code.
Exim4U is a Web-based user interface and integrated software configuration for the Exim message transfer agent (MTA). Using any modern Web browser, you can use it to manage Exim email domains, user accounts, aliases, forwarders, and much more. Exim4U is a derivative work of the Virtual Exim (Vexim) project.
WAWAS is a full PHP application server. The main server core listens to any IP/port and passes data to any mounted protocol on the listener. Implemented protocols are HTTP1.1/1.0, Comet, Telnet, DNS, mail, and FTP. Each protocol runs modules that build response data based on the requests. Memory object persistence allows data and caches to be shared across protocols or time. All configuration uses XML. It can be launched as a daemon, with or without forked workers, and is nearly as fast as Apache in preliminary tests.
claws-mail-indicator is a simple plug-in which adds support to Claws Mail for the Ubuntu indicators. Notifications are displayed in the Messaging menu, with the option to display a notification bubble each time new messages arrive. It was developed and tested on Ubuntu 11.04 (Natty) 64-bit.