How do I add my email signature to Apple Mail on macOS?
Open your signature on htmlsig.com in Chrome or Firefox — avoid Safari, which can cause layout errors.
Select your signature and copy it to your clipboard.
Open Apple Mail and go to Mail > Settings > Signatures.
Uncheck Always Match My Default Message Font before pasting, so your signature keeps its own formatting.
Create a new signature and paste your copied signature into it.
Note: after pasting, your images may show as empty boxes in the settings window. This is normal — close the settings window and start composing a new email, and your images will display correctly.
To confirm it's working, create a new email and check that your signature appears. If it doesn't show up automatically, make sure it's selected in the signature dropdown in your new email window.
