To enable IMAP in Gmail:
- Sign in to Gmail
- Click the gear icon in the upper-right and select Gmail settings at the top of any Gmail page (it's not possible to enable IMAP while using the basic HTML interface, be sure you are using standard view to see these options)
- Click Forwarding and POP/IMAP
- Select Enable IMAP
Note: IMAP syncs the actions you take in Outlook Express or Apple Mail with Gmail so if you read a message in your mail client, it'll be marked as read in Gmail.
Once IMAP is enabled on your account configure the 'Mail' app on the iPhone:
- Open the Settings app on your device (gears icon)
- Tap Mail, Contacts, Calendars (a few up from the bottom of the list, will need to scroll down)
- Tap Add Account...
- Tap Gmail
- Enter your account information, being sure to use your full Google Apps email address, including @your-domain.com. Must be the actual account address, not a nickname. i.e. [email protected]
- Tap Next
- Tap Save (you might get a certificate warning, if you do click continue)
You can then choose the email app (envelope icon) and then Accounts (on top left, if more than one account set up) to switch to the new account.
Note: When you delete a message from the iPhone it will archive it to a label called "Deleted Messages", which shows up as "Trash" on the iPhone. It's easiest to actually delete these later from a browser on your computer which will then move them to the actual gmail trash.