The following directions will assist you in adding a custom signature to Outlook for Mac.
- Select “Preferences….”, then “Signatures”
- Select “+” to add a new signature.
- Give your signature a name, build or paste your signature in the body and select “Save” (3).
Make your selections and close this box.
If you have selected the signature in the "New message" dialog, your signature will automatically be added to new emails you create.