Granted, I haven't really educated myself on this whole "Push vs. Pull" thing, but is there some good reason I can't get mail pushed to me? Is it up to the mail provider (i.e. Google) to supply that functionality? I've heard it can be done using Exchange, but I'd rather not setup my own exchange server to route my gmail through...
Blame Google on that one. IIRC Yahoo mail on the iPhone offers push mail using IMAP and IDLE commands to keep a persistent connection to the server. I have my own IMAP server and I use this method as well. It's as good as my BlackBerry push e-mail through Sprint. Apparently Google either doesn't fully support the IDLE command or has time limits -- otherwise it should work just like Yahoo IMAP/IDEL push.
I don't think it's Apple that is restricting this, since Yahoo! email accounts are pushed to the device just fine. I still don't know what pros their are for Google to not support it though. It seems like bad business.
Heh. Well, I dunno what to tell you. You can probably do some sort of auto-forward + reply-to: address kludge to fake it.
It sucks, but to be honest I personally don't mind. I've been making apps with the push API and beta testing the AIM client with push and I have a feeling I'm going to be turning push notifications OFF for most services - I'm already getting too many notifications and I'm not using any "real" apps yet, just beta stuff. If I had push email on, my phone's battery would die in about 45 minutes.
I received an email from Apple asking developers to test out a version of AIM with push capability. It drained my battery faster than checking email every 15 minutes (that is, the phone didn't last a day without requiring another charge). I turned it off pretty quickly.