GNU JavaMail is a free implementation of the JavaMail API
specification, version 1.3. All the code has been written from scratch
without reference to Sun's code, which allows GNU JavaMail to be used
on a completely free operating system such as GNU/Linux or the Hurd.
The code is optimized to work with free Java implementations, nothing
prevents it from being used with any compliant JVM. GNU JavaMail
provides a protocol-independent framework for building mail client
applications in Java. The API itself provides a complete MIME
implementation, and drivers for individual messaging protocols, known
as providers, can be plugged into the JavaMail framework dynamically.
Several providers, implementing Internet standard protocols, are
included with GNU JavaMail. These include: SMTP IMAP POP3 NNTP
including posting to news servers The UNIX mbox format Dan Bernstein's
Maildir format All these providers are feature-complete, and provide
cryptographically secure access where relevant.