How do I add an email signature in AirMail for Mac? Sebastien Barrau November 09, 2016 17:50 Updated Please follow the instructions in the video. You will need to copy the HTML of your signature and paste that into AirMail. Related articles How do I add an email signature in Apple Mail on macOS? How do I add an email signature in Outlook 2016 for Mac? How do I add a email signature to Thunderbird ? Comments 0 comments Please sign in to leave a comment.