iPhone ActiveSync on Gmail, with Custom From: Address

I finally figured out how to get my iPhone to use ActiveSync for Gmail, while still allowing me to use a custom reply-to address. Your mileage may vary, but here you go.

NOTE: This procedure worked for me, but may not work for you. Backup your iPhone before trying it!

(Outside the scope of this document, you must already have 2 accounts setup on your iPhone: (1) An IMAP account that is downloading email from gmail.com, and (2) an ActiveSync account that you're using to sync up Contacts and Calendars. And you must have your vanity reply-to address already registered within your Gmail account. For the purpose of this article, I'll say my vanity address is me@mydomain.com.)

So, with the above as our starting point.

1. Go into iPhone Settings, then click "Mail/Contacts/Calendars."
   
   
2. Click on the "Fetch New Data" option.
   
   
3. Scroll down and click on "Advanced."
   
   
4. Set your IMAP account to "Manual."
   
   
5. Set your ActiveSync account to "Push."
   
   
6. Back out 2 screens so that you're on the "Mail/Contacts/Calendars" settings area.
   
   
7. Click on your ActiveSync account, and then turn Mail ON. (Calendar and Contacts are probably already ON.)
   
   
8. Click the "Account Info" button at the top.
   
   
9. Change the "Email" field to be your vanity reply-to address, e.g. me@mydomain.com.
   
   
10. Back out 2 screens, to the "Mail/Contacts/Calendars" screen.
    
    
11. Click on your IMAP account.
    
    
12. Underneath "IMAP Account Information," there should be a field named "Address." Edit that field to use that same vanity address, e.g. me@mydomain.com.
    
    
13. Below that are 3 fields for "Incoming Mail Server." Erase the text in each of those 3 fields. (We do this so that your phone won't ever try downloading mail via IMAP.)
    
    
14. Now back out to the main screen (the home screen).
    
    
15. Start the Mail app, and once you're in the inbox, click the back button, and then once more until you see your 2 accounts shown.
    
    
16. Click the ActiveSync account, and then click "Inbox."

Now you should be in your ActiveSync inbox, and it will download your email.

If you start a new message, or reply to an existing message, it should use your me@mydomain.com vanity address as the From: address. The gmail.com address is still exposed in the "hidden" headers, like Return-Path, but there's not much you can do about that.

NOTE: This worked for me, but may not work for you. Backup your iPhone before trying!