This didn't address his issue at all.  I am having the same issue - Quickbooks has implanted unwanted (and inappropriate) salutations, improper punctuation, their own canned email (which leads customers to believe we take payments we do not, i.e. Venmo).  There is no way to get rid of these changes.  ADDRESS THE ACTUAL ISSUE HERE SUPPORT STAFF.  And stop updating the few parts of the program that are fine AS IS.