If you're running a cPanel based server, try running with IMAP port
993, Mailbox
INBOX and Use SSL
Yes.
Also, the IMAP User Name is bounce+yourdomain.com (assuming
bounce@yourdomain.com is the actual email you created, of course).
You have no idea how much grief I had trying to log on from my email app before I learned to put a + in the login name instead of the @
Fillip