How to install your email signature in Spark Mail on iOS Sebastien Barrau December 12, 2016 14:32 Updated You can download Spark for free on the Apple App store. Related articles How do I add a signature to Apple Mail on iOS? How do I add an email signature in Apple Mail on macOS? How do I add a logo and what size should it be? How do I add an email signature in AirMail for Mac? How to install your email signature in Polymail on iOS Comments 0 comments Please sign in to leave a comment.