A number of fixes were made for IMAP in hot fix 22.214.171.124.
This issue is to merge V4.2-BUG-FIX r91709 forwards to 5.0.N. This includes merging the changes made to greenmail, which has already been changed on the 5.0.N branch.
There was still an outstanding problems described here to do with moving multiple entries in Outlook 2011. It appears that there is a problem in this version of Outlook that we are unable to find a workaround for.