<<I also did a fair bit of computer programming when I was younger and I have a hard time believing that there in fact was anything patentable about wireless e-mail in 1991.>>
Absolutely. There were people infringing on these patents in the 1970's and doing a better job of it than NTP or Telefind or ESA Telecom or whatever entity the alleged inventor's scheyster patent lawyer (former patent examiner) says developed this alleged technology.
By the time the 1980's rolled around anything relating to gating, routing, transmitting or receiving network data and services wirelessly was already toytime and there were kids with soldering irons, VIC-20's and Novice tickets who were blowing the doors off the systems, methods and practices that these patents claim as novel. I guess that there's some kind of special protection for innovations that retard the state of the art and Telefind got that protection for their "wireless mailbox" for the AT&T Safari NSX/20 --- the dustbin of history where bad products based on dumb ideas always go.