Go to the Settings page (step1) then click on From Emails (step2).
Step 1: Click on the gear icon, then on Settings in the drop-down menu.
Step 2: On Settings page, click on the From Emails tab on the left side.
Fill in the Add From Email form and click Save.
The newly created email template will show under From Email list.
Click on the created email template to edit it.
Enable the Primary option to have your agency use this email template for all email communications.