Add an email signature to Outlook 2013 messages

Create personalized signatures that appear at the bottom of your messages. Signatures can include text, images, your Electronic Business Card, a logo, or even an image of your handwritten signature.

Create a signature

1. In a new message, click Signature >Signatures.

2. On the Email Signature tab, click New.

Add a signature

In a new message, click Signature, and then click the signature that you want.

Source: Microsoft.com