Email wasn't phased out at all, but SHA-2 was never implemented in the first place, but in the years the machine was developed for, SHA-2 didn't exist, or at least was not in use.
But the big dogs (Gmail, Yahoo, Office365) all promised a few years ago to implement it, and started to enforce it in January 2016 in a staggered rollout, as soon as they did, all the smaller ones jumped on board and did so as well.
Lots of things didn't and don't support it, printers are a big one though, and if a company isn't selling the printer, they make nothing by developing new firmware for it, so they don't.
Had FujiXerox ever guaranteed that they would support SHA-2, they would have coded a fix, but they didn't. They did release fixes for all the machines that they still developed for, the oldest models I know of were the 53XX and the 72XX models, and that was only because enough paying customers demanded it.
But since your model didn't get a fix, you would basically need an inhouse unauthenticated, or outdated server to use, or a mediary, like SMTP2Go