iCloud 
Create an email signature
You can automatically add a text signature including your name, title, phone number, favorite saying, and so on to every email you send using iCloud Mail. If your devices have the iCloud Mail feature turned on, changes you make to your iCloud Mail signatures appear on those devices.
Create an email signature
In iCloud Mail, choose Preferences from the Action pop-up menu
in the sidebar.
Click Composing.
Select “Add a signature,” then type your signature text in the field provided.
Click Done.
Stop adding an email signature automatically
In iCloud Mail, choose Preferences from the Action pop-up menu
in the sidebar.
Click Composing.
Deselect “Add a signature.”
Click Done.