> The last I knew, in the U.S. the fax still carried some legal recognition/privileges that email did not.
Much of this is the direct consequence of fax being carried over the POTS copper telephone network, where there is some belief (not necessarily accurate in today's world) that the link between sender and receiver over a POTS line is free of "men in the middle". Therefore fax is viewed as 'secure' due to this belief.
In really olden times, you had to talk to the switchboard operator to connect your call. It was free of men in the middle only by dint of the fact that most operators were women.
Partly, but also because it is easier to authenticate as not being spoofed or faked. Faxes have a 'sending number' that is transmitted as part of the protocol, and caller ID allows checking the source, whereas email senders can be very easily changed. However, even the fax may not be secure enough - I worked for a gold bullion trading firm in the 90s where they used faxes for secondary trade confirmation, but sent a telex with the data as then main mechanism, because the telex network was considered more secure than the PSTN and relying on fax sender numbers.
They also used X.25 a lot, as they didn't trust the fancy new TCP/IP stuff that was around, though, so there's that...
> Partly, but also because it is easier to authenticate as not being spoofed or faked. Faxes have a 'sending number' that is transmitted as part of the protocol, and caller ID allows checking the source, whereas email senders can be very easily changed.
In the US, there is a widespread problem of robocalls that appear to originate from the same exchange as the phone number assigned to the cell phone. Couldn't this also affect faxes?
Unlike email, caller id does not have the equivalent of SPF[1], DKIM[2] or DMARC[3].
Yeah, I should have emphasized the historical aspect more - this was the nineties, when those protocols didn't exist and SSL wasn't as widely deployed. Although, it's probably still a sort of vestigial, holdover opinion from then, even now?
Much of this is the direct consequence of fax being carried over the POTS copper telephone network, where there is some belief (not necessarily accurate in today's world) that the link between sender and receiver over a POTS line is free of "men in the middle". Therefore fax is viewed as 'secure' due to this belief.