Links
Client
http://imapclient.freshfoo.com/ IMAPClient aims to be a easy-to-use, Pythonic and complete IMAP client library with no dependencies outside the Python standard library.
Server
http://lamsonproject.org/ The Python SMTP Server
Testing
Tools
IMAP Backup Tool This program incrementally backs up IMAP folders to local mbox files. New messages are appended to the folder’s mbox file. Copy in the source repository http://toybox/hg/utility/file/tip/imapbackup.py