Google announced that they have a solution to get rid of the "on behalf of" notification in Gmail by using the SMTP (send mail) server of the address that you are sending mail on behalf of. The process is quite simple:
- Log into your Gmail account
- Click "Settings"
- Click "Accounts"
- In the "Send mail as" section click "Edit Info" next to one of the accounts
- Set your name and click to the next screen
- Click "Use the other e-mail provider's SMTP servers"
- You will be presented with SMTP server address, username, and password fields along with a SSL checkbox and a port drop-down
- The SMTP server is: smtp.gmail.com (by default the system pre-populates the custom domain, so you need to make sure that you change this)
- Your username is:
@ (i.e., email@example.com | you have to put your entire e-mail address in there for the Google SMTP server to authenticate you)
- You password is: whatever password you use for that other account (not necessarily your primary Gmail account password)
- Click the SSL box; the port automatically sets correctly
- The system will verify your credentials and will only return you to the configuration screen if there is a problem.