[jcrawfordor]

Are your clients on physical fax machines or an internet-based fax service? I use fax for business but I use Phaxio, and I think more than half the people I exchange faxes with are also using a fax service. This has the comical result of my producing a PDF file then paying someone to modulate it into noises that someone else will demodulate back into a PDF to deliver to the recipient. It's like e-mail if the intermediary servers lossily recompressed the attachments.

[fluxquanta]

The clients I work with tend to still use physical fax machines to send/receive financing details to small banks and credit unions. The banks themselves probably use some sort of internet service, or at least I hope they do.