said by kitsune: i left it default, the past 3 months stuff doesn't seem to be syncing properly if I delete or read something on my iPhone. When I get home from work and open iMail i see them Unread
If you go to the gmail website and go to settings. Under "Labels" you will see all your folders and can control whether they sync with IMAP. I would suggest disabling All Mail it just creates confusion. Also under "Forward and IMAP/POP" there is the controls for how it handles deleting emails.