How about a JPEG-borne virus instead? https://research.checkpoint.com/sending-fax-back-to-the-dark...
https://www.youtube.com/watch?v=qLCE8spVX9Q
> "See for yourself first-hand as we give a live demonstration of the first ever full fax exploitation, leading to complete control over the entire device as well as the network, using nothing but a standard telephone line. "
Maybe it's time for you to find another tax preparer. Mine accepts encrypted documents with her public key.
If he wants to stick to his old-school fax machine and keeps me on the right side of the tax agencies, I can accommodate his preferences on tech.
Not as long as you can send faxes from the Internet.
FaxZero even allows you to put in the phone number the fax comes from. It's $1.99/fax to remove the FaxZero cover letter, and they accept PayPal.
(Also, someone with the username iptel might know a bit about this.)
Edit: and exactly how that differs from SMTP?