

Replace the signature contents on the right with some placeholder text. Name the signature something meaningful in the central column. In Apple Mail, open Preferences > Signatures. However, the process has changed ever so slightly for the new macOS Catalina (10.15). You can even find one of my other tutorials on how to add HTML Signatures in There are plenty of tutorials online to create an HTML signature in Apple Mail with older versions of macOS/OS X. How to Make an HTML Signature in Apple Mail for macOS Catalina 10.15
