A signature is a bit of personalized text (such as your contact information or a favorite quote) that is automatically inserted at the bottom of every message you send. 

 To create a signature:

  1. Sign in to Gmail.
  2. Click Settings at the top of any Gmail page.
  3. Enter your new signature text in the box at the bottom of the page next to the Signature option. As you type, the radio button will shift from No Signature to the text box.
  4. Click Save Changes.

Signatures are separated from the rest of your message by two dashes.

If you don't want your signature to appear on a specific message, you can delete it manually before sending the message. Just highlight the text and delete it before sending.

 

Read more:
Add a link to your portfolio in your email signature