Gmail – How to Send Email from Alias Address

You need to do the following:

1. Set up the plus address on the original account (even though you won't be using it directly from that interface).
2. Add the account's SMTP information, using the following settings:
   • Email: Your plus address (user+sample@example.com)
   • Username: Either your plus address (user+sample@example.com) or your base address (user@example.com) will work. In fact, it completely ignores anything afer the +, so even an address that wasn't added as a "Send As" in step 1 (user+foo@example.com) will work.
   • Password: The password for user@example.com.

If you don't do the first step, the account isn't permitted to send mail via that plus address and any attempts made at sending via that plus address (user+sample@example.com) will actually be sent from the base address (user@example.com).

Note: the plus address will appear in most headers when the email is sent (e.g. Return-Path, From, Received) but the base address will still be shown in the Sender field. However, most clients should show the From field and hide the Sender field from the user.