How to Create a Signature for Your Outlook 2013 Messages
Click the OK button in the Outlook Options window.
The Outlook Options window closes.
Your new signature will now appear on every new message you send. If you create more than one signature, you can switch to a different default signature by following Steps 1 through 3 and then choosing the signature you want from the New Messages menu in the Choose Default Signature section.
If you want to include a signature in your replies and forwards, choose the signature you want from the Replies/Forwards menu in the Choose Default Signature section.