Hey there, @ntuitiveitisnot.

Thanks for following up on this thread. 

My colleague, @Anna S, have already answered a similar question you've posted. You can refer to this link if you haven't already checked it yet: https://quickbooks.intuit.com/learn-support/en-us/other-questions/invoice-email-message-adding-track....

Please feel free to comment below if you have any more questions or concerns. Have a safe and productive weekend ahead!