1. First click “settings”.
2. Then click “Accounts and Import” followed by “Add another email address you own”.
3. Follow the instructions to add your name and email address. Treat as an alias should be checked.
4. Here’s where it gets tricky. SMTP Server should be smtp.gmail.com, username is your gmail address, but password is different.
5. Follow this link to create an App Password: https://security.google.com/settings/security/apppasswords, log in to your gmail address.
6. Click “Select App”, then “Other”.
7. Call it Gmail, or whatever you want.
8. Copy the password, and paste it onto the screen from before:
9. Click “Add Account”, and you should be good.