/usr/local/imap_tools/imapcopy.pl -S server1.example.com/sales@example.com/secret -D server2.example.com/sales@example.com/secret
http://www.howtoforge.com/how-to-migrate-mailboxes-between-imap-servers-with-imap-tools
http://www.athensfbc.com/imap_tools/
http://www.athensfbc.com/imap_tools/details.html#imapcopy
http://www.athensfbc.com/imap_tools/imapcopy_example.html
http://www.athensfbc.com/imap-tools/IMAP_Tools_User_Guide.pdf
http://manurevah.com/blah/en/p/Migrate-emails-with-Imapcopy
http://home.arcor.de/armin.diehl/imapcopy/