Here is some more information about moving Maildir's.
THIS IS A LAST DITCH RECOVERY METHOD AND IS NOT SUPPORTED AND NOT RECOMMENDED
http://forums.contribs.org/index.php/topic,42280.15.htmlIf you use SME's built in backup or one of the backup contribs from this site, monitor your backup logs and test your restore procedures, you should never have to go through the above pain.
Back it up!!!!
Check the backup logs or emails daily!!!!!
Test restore it monthly!!!!!!
unless, of course, you don't care about your data.