If the email address you use most often for sending is different from what Gmail picks initially in new messages, you can change that default — and make your favored address Gmail's, too.
Change the Default Sending Account in Gmail
To choose the account and email address that is set as the default when you start composing a new email message in Gmail:
- Click the Settings gear in your Gmail's toolbar.
- Select the Settings item from the menu that has popped out.
- Go to the Accounts and Import category.
- Click make default next to the desired name and email address under Send mail as:.
(Updated July 2012)