email customization

Hi, We are implementing electronic signature capture on some of our documents and I'm currently in the process of setting up outgoing notifications to customer once signature has been obtained. i.e signing ceremony is complete. For speed, I used the sandbox. I believe this is a basic functionality that has been around for a couple of versions. I wanted to know if the completion email sent to the customer can be customized per our organization requirements like affixing our company logo, incorporating our company helpdesk number etc... I’ve attached the raw images if it helps. I highlighted few areas where I would think needs customization. Regards,