Office 365 (Outlook Client for Mac) - Create a Signature and Insert Into a Message
You can manually or automatically add personalized signatures in your e-mail messages. Signatures in Outlook can include texts, links, and images such as company logos.
For the most current information, please check out the following Microsoft help article: https://support.office.com/en-us/article/create-and-insert-a-signature-in-outlook-for-mac-f4d21492-0956-4429-95ad-2769745b539c