How do I add / install my signature to Apple Mail?

For Apple Mail on Mac:

1. Copy your Mail Sign Desk signature.
   


2. Open Mail.
   


3. Go to Settings/Preferences → Signatures.
   


4. Select the appropriate email account.
   


5. Create a new signature.
   


6. Paste your signature.
   


7. Make sure the correct signature is selected for the account.
   


8. Send yourself a test email.
   

Important: Apple Mail can sometimes alter formatting when signatures are copied incorrectly, so always test the final result.