mstor is an extensible framework for JavaMail local store providers. By default mstor provides support for the mbox email storage format and Java Content Repositories (JCRs).
Great library for local storage with Javamail!
This project adds aa very useful provider to JavaMail: without it you can't save a complete mail message to disk. The code is reliable and fast, though the documentation is a little skimpy: some example code would be very helpful.