Gmail – How to Add a Banner to a Forwarded Email

Google has this listed as a known limitation. The only thing you could do is add the nickname as a 2nd email account (not exchange) on the phone and then use that for sending email.

There is no elegant solution but here is one that should do what you want:

1. Using your Google Apps account, create a secondary user: garbagecollection@mydomain.com
2. Set the catch-all (in Control Panel for domain, email settings) to go to garbagecollection@mydomain.com
3. Write a Google Apps Script which scans the inbox periodically (every 5 min?, daily?)
4. The script would:
   1. Automatically add new addresses to a control spreadsheet
   2. create a label for each new address in your main email account
   3. forward each email to your main account (if not black listed in spreadsheet)
   4. apply the label in your main account

It would work as follows:

You create registration specific email addresses such as firstname.lastname.amazon@mydomain.com because the garbagecollection@mydomain.com is a catch-all, it will accept any email. The script records all new addresses it in the spreadsheet. When you want to stop receiving email, you flag it in the spreadsheet and the script deletes the email rather than forwarding it.