I click Mail, it opens for 2 seconds, then closes down to main menu?!?!?

mcwhan, the only thing I can offer is that the same thing was happening for me (in addition to what I already mentioned above), where messages that I deleted would appear again after it shut down. I finally figured out which message was causing the problem, but couldn't keep email open long enough to delete it, so deleted and re-added the account causing the problem. Fortunately this worked for me.

After you delete & re-add your account, are the same messages returning to your phone inbox?

Sorry Dan but my tech level is pretty low, so you're going to have to break it down a bit more for me... when you say "in Mail.app on OS X" - I have no idea what or where that means.

Janice

Just wanted to throw in my experience - Mail suddenly started crashing constantly, I couldn't keep it open for more than a few seconds. Rebooting didn't help, home & power button restart didn't help, airplane mode was fine. I sync my mail with Thunderbird on my laptop as well, so I took a bunch of messages I'd received since the last time Mail seemed to be working, and moved them to a local offline folder - that did the trick. A few of them were bounced messages that some server had fed back at me - I suspect one of them had a wonky header and Mail was just freaking out at it.

Not sure what you'd do if you don't have another computer to sync to, though... I guess find another computer, go into Webmail, and clear out the suspects.