You can add an email signature to the emails being sent from Zahara such as Approval emails. You can also add a logo to the email signatures; this will likely be an image stored on your own website. 


Edit the template

Head into Business Settings and then into the Templates section.
Below is the email signature for sending a purchase order to the supplier:
In terms of the actual logo, you will need to reference an image on your website. Click the Image icon and then enter a URL – Example: