Posting this in hopes that others will find this useful.
One of our customers is using hMailserver v4.4 Build 270 (not latest) with RoundCube 0.1rc2. When a user with a very large mailbox attempts to log in they never reach the inbox as the php timeout is reached (120s).
After enabling debugging logs on the mail server it appears that the IMAP SORT extension in hMailserver is the culprit. It takes over four minutes to complete the sort (23000+ messages) during which time PHP and RoundCube timeout.
Disabling the IMAP SORT extension in hMailserver enables the user to log into his mailbox within a matter of seconds.
So if you are having users who complain about excessive login times then try to disable the IMAP SORT extension on the mail server.
We'll file a separate report with hMailserver as we checked the change log and it does not appear that the latest version addressed any IMAP SORT functionality.
