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.
Lamson is an SMTP server adopts a modern Web application framework design. Rather than bizarre flat file "databases" and hashtable stores, Lamson uses anything that Python does to store data, including Django's ORM, web.py's simple database library, Tokyo Tyrant, Lightcloud, Python's Shelve (not recommended), Raw SQLite3, SQLObject, CouchDB, Mongo DB, and SQLAlchemy.