Sign PDF's directly in Mail
Overview:
It might be the 21st century, but we're still using squiggles on a piece of paper to agree to all manner of things. If you are emailed a PDF to sign, though, you don't have to faff about printing it, signing it, then scanning it back in: you can actually sign it right in Mail. Drag a PDF into the email you're sending, hover over it then at the top right you'll see a little arrow button appear; click it, and you get a range of Markup options, including one for signing documents. Best of all, you can either add your signature by holding a signed piece of paper up to the webcam on your Mac – and it does a great job of cutting it out of the background – or by drawing on your trackpad.Got an iPad stylus? Try using that instead of your finger!
here's some step by step instructions.
Drag and drop PDF onto Mail
Drag the desired PDF onto the MAIL icon in your dock
Click the arrow icon in the upper right corner and select markup

From the Markup menu select the signature tool, then click on the desired signature (if you have more than one)

The signature can then be dragged to appropriate area on the PDF and if required resized by selecting the corner of the signature and dragging, then click Done
