Last week we announced we were providing you with free IMAP access and said we would roll out the feature over time as fast as we could. I'm happy to say that all Gmail users can now enable IMAP and sync their inbox across devices. Right now you'll only see IMAP settings in Gmail if you're using the English (US) interface, but IMAP will appear for all languages in the coming weeks. Check out our Help Center to learn more about IMAP, or watch our video to learn how to quickly set it up on the iPhone.
Update: I'm also pleased to say that Gmail users with custom email addresses (through Google Apps) can now enable IMAP too.
