Automatic e-mail checking not working

[lostpilot28]

I've done a quick search for this, but can't find an answer. My Eris doesn't seem to automatically check for e-mail in the middle of the night. That's not the big problem, since I'm sleeping...when I grab my phone in the morning and use it, whether to make a call or whatever, it still doesn't automatically check for e-mail.

As a matter of fact, it seems like if I manually "refresh" my e-mail it will check for new e-mail, but then go back to not checking regularly...although later on in the day it seems like it will start checking at some point. Weird, eh?

I've got 3 e-mail accounts: gmail, pop3, and yahoo. They're all setup to retrieve e-mail automatically but at different times (30 min, 30 min, 15 min, respectively). My mobile network is turned on, too. Any ideas?

Thanks!