This article is for the Outlook App known as Outlook (New) not Outlook Desktop/Classic.
Showing the From address selector allows you to select which email address your email will appear to come from. You must have Send As permissions for the account chosen.
- Click the Gear in the top right to open the Options window
- Click "Mail" then "Compose and reply"
- Scroll towards the middle of the options list until you see "Addresses to send from"
- Check the addresses you would like from the autopopulated list and click "Save" at the bottom of the window.
- Close the Options window
- When you create a new email, you now should see the list of available from addresses next to the Send button (by default, replies will come from the same email address the original email was sent to)