How to Add a Signature to Your Apple Mail E-Mails

The Signatures pane opens.

Your signature options show up here.

Press Return to save the new name.

Now open your HTML signature in an editor, copy all and paste it to the text box above

Here you can choose which one you want to use or to use them all randomly or in sequence.

If you prefer the signature to appear above the quoted text in a reply, select the Place Signature above Quoted Text check box.