To optimize the design for emailing receipts, size your company logo to: 320px wide (ANY HEIGHT)
Also make sure your image is in a .bmp format such as companylogo.bmp
You can then modify the sizing using the PC Settings under TOOLS > ADMINISTRATION
Use the search screen to see all of the image sizing for all of your PC's.
If you are not using HTML email themes, POS email receipts will appear as shown below.
Example of a Point of Sale Email Receipts to different email providers, each may look slightly different:
Email Receipt to an Outlook App
Email Receipt to a Gmail account in Chrome browser:
Email Receipt to a Yahoo account in a Chrome browser: