I have 2 GMail accounts, 1 exchange & 1 IMAP. Exchange pushes just like it should, I've had no issues with it. The IMAP one is only set to retrieve once an hour and that's exactly when emails come through ( usually in bunches ).
Every once in a while I will get a message that says my exchange password is incorrect. My gmail is set up imap and i push to my iphone. Maybe I should turn push off and just fetch. Might take care of the problem. Any opinions on this? Let me know.