A tool written in PHP which allows you to migrate OR archive your e-mail from one IMAP server to another. This becomes especially useful when one of the IMAP servers is non-UNIX (ie Exchange Server).
Problematic. I've spent hours to make it work and alas it does the job. Today Apr 21, 2012 it's nearly a year after the last update. If you do not want to update it, please leave it to me.