If you would like to include a signature with your emails when using the Send Email or Create Draft actions, you can use the dropdown to select a corresponding default signature HTML for an email/alias on your Gmail account.
If you do not see any signature HTML next to an email/alias in the signature dropdown, please verify that you have configured a default signature for the email/alias in your Gmail account settings. At this time, we're only able to retrieve signatures from your account if they set within your Gmail account settings Signature Default > For New Emails Use dropdown.