I successfully got GMAIL to work beautifully across my iPhone, MacBookPro (mail.app) and Thunderbird on Windows. Here's how I did it: 1. In GMail, I forwarded all of my mail to a free 2gb AIM mail account. (similar space, similar conditions). (GMail Spam filters own.) 2. I setup my accounts in my email clients to send mail from my GMail SMTP account, on the GMail server. I also set up my clients to receive inbound from imap.aim.com. 3. I set both of these up on my Thunderbird, and my Mail.app. I then synced it via iTunes to my iPhone.. Sure, it's common sense, maybe? But it works. And it's completely free.