On the numbers here: The IMAP test ends up with 4 messages in the inbox because we cram one in by default because of our timezone detection needs.  I think this test would really be fine with just 1 message in the inbox, so maybe don't add any for IMAP, and just add 1 for other cases.  This will make the log a little easier to look at and makes it more practical for us to place some more explicit expectations about what happens in the test.  (More below on that.)