Disable icloud for Mail on macOS

If you have issues with your email signature in macOS, we recommand you to disable "iCloud data for Mail" which only purpose is to sync a few settings between two macs and is quite buggy

Go to "Apple Menu > System Settings > Click on your name at the top of the list > iCloud Drive > Apps using iCloud"

In the list of Apps using iCloud , disable "Mail" , restart the Mail App