Do not investigate in the 2342 tools that exist for migrating IMAP accounts from one server to another. They all suck.
Try your luck with
imapsync
Show archive.org snapshot
.
We have no clue why the guys suggest buying the script on their site, maybe they missed removing that part after this April fool's trick.
Go to https://fedorahosted.org/released/imapsync/ Show archive.org snapshot and get the sources there.
Posted by Thomas Eisenbarth to makandra dev (2013-01-31 10:53)