I am having the same problem with Quickbooks invoice emails. I have a template that I modify with customer specific or other timely information for each customer that I send an invoice to. I generate the invoice email from Quickbooks. Then edit it while it is open as an Outlook email message until it contains the customer specific information I wanted to add. Then I click send. I always to a CC to my company email.
Both the CC and the copy in the Outlook Send folder are reverted back to unedited template. I was embarrassingly alerted to it by a customer yesterday. I spent 10 hours yesterday trying various things to get the invoice email to keep the edits as well as checking the internet to see if anyone else had a solution or workaround.
No workaround or solution found.
A side note, when a Quickbooks invoice email is open, no other Outlook actions can be taken. That is, I cannot open another email while the QB invoice email is open (e.g., to copy and paste from there to the new email).
