Need to change or set a return email address in the macOS Mail app? It’s easy.
With Mail open…
- Click “Mail” in the upper left-hand corner of your screen.
- Select “Preferences”
- Select the “Composing” tab
- Click “Automatically select best account”
You’ll see a list of your email accounts. Select the one that you wish to be the default return email address.
That said, the Mail app is pretty smart and is pretty much reliable at associating the email address with a particular account, which is why I don’t set up a specific return address in Mail.
Also, when you reply to an email, you can choose a different return email address than the one associated with the account. Just click and hold the From field and a list of all your email addresses will pop up. Choose the one you want.