For those who are too young, a fax machine is this arcane device that used to be everywhere, like a remote photocopier.
Got the US patent dated 2013. Was the lawyer pulling my leg?
Which is all to say that it wouldn't surprise me if there were a legal requirement for an "original document", and if that requirement could only be met by physical mail or fax.
As a former fax server administrator (and troubleshooter/maintainer of everyday standalone fax machines), I think the point-to-point nature of traditional, non-Internet fax is the killer feature: no packets split up and resting on intermediate servers, etc. Fax servers have one or more individual fax modem cards, so the only network involved is before or after the actual fax transmission.
I know fax is outdated. There are other effective technologies to replace it. But I've found myself more than once speaking up as a defender of the technology because, as originally used and codified into law, it serves a specific purpose and, as a bonus, if you know how to use a photocopier and a telephone it's drop-dead simple to use.
(Again, like my other comments here, this is just my opinion, not that of the USPTO or US government.)
This comes up almost immediately when studying to be a parent examiner.
> This comes up almost immediately when studying to be a parent examiner.
To my knowledge, this wasn't part of my training. Perhaps you mean studying for the patent bar? I'm not a patent attorney or agent, just an examiner.
AFAIK email to fax (and vice-versa) converters have existed for a while ?
I'm much more annoyed that in 2022 we are still misusing pdf, treating it as a digital-first format rather than one more appropriate for archival of paper documents... (and with the associated "pdfs cannot be modified" myth)