[MlMt] Ghost mailboxes

[Randall Gellens]

Thanks to Bill's suggestion that the culprit was the subscription list, 
since I didn't believe that to be the case, I modified the accounts on 
my IMAP server to permit plain text authentication, SSHed in to the 
server system, and used telnet to login to the accounts and poke around. 
  The ghost mailboxes did exist, and when I tried to DELETE them, the 
IMAP server replied with "NO mailbox is in use, or folder is not empty". 
  Since I knew the ghost mailboxes were empty and verified that they 
were by SELECTing them, I figured they were busy perhaps due to a bug on 
the server, so I restarted the server, relogged in, and this time I 
could DELETE them.

So, sorry to assume it was a bug in MailMate that was the culprit.  
However, it might be good if when MM encounters an error deleting a 
mailbox, it says something (I couldn't see anything in the activity 
window, and there was no error reported in the UI).

--Randall