If I attach an Adobe PDF to emails....some pdfs get garbled in some places....but not all pdfs get garbled. If using the the 2nd account on my Thunderbird, the garbled PDFs are NOT garbled. Any ideas?

'''bold text''' I'll try this again. I scanned some documents that included a notary stamp. Opening them in Adobe reader they are fine. I attached them to an email and sent them off. Get a return message that the notary stamp is garbled. I opened the email from my SENT folder and yes, they are garbled. Secretary also uses Thunderbird. She sends the same file and the notary stamps are fine. In fact, her account is in the same Thunderbird as mine. If she sends via MY account in her Thunderbird the notary stamps are garbled. If she uses HER account in the same Thunderbird (i.e. same computer, same program, etc.) program they are fine. Any guesses on what is happening?