How to add signature to mail account on mac

- How to add signature to mail on mac
- How to add signature to mail on macbook
- How to add signature to mail app on mac
- How to add html signature to mail mac
- How to add signature to mail on macbook pro
- How to add signature to mail on macbook air
- How to add signature in outlook
- How to add signature in gmail
- How to add sign in outlook