getmail 6 is a flexible, extensible mail retrieval system with support for
POP3, IMAP4, SSL variants of both, maildirs, mboxrd files, external MDAs,
arbitrary message filtering, single-user and domain-mailboxes,
and many other useful features.

• getmail 6 @ GitHub.

complete mail server
SMTP + IMAP + POP3 + Antispam + Antivirus
Web administration + Web email ...on your server in ~5 minutes

GreenMail is an open source, intuitive and easy-to-use test suite of email servers for testing purposes.

Typical use cases include mail integration testing or a lightweight sand boxed mail server for development. GreenMail is the first and only library that offers a test framework for both receiving and retrieving emails from Java.