After fiddling with images for a while, I realized that I hadn't checked my email in quite a few hours. I decided to attempt it on the 5150.
I identified a few routes that I could take to attack the Internet problem. The most challenging approach involved hooking up some sort of ethernet adapter to the 5150, and then running programs on the IBM that would allow Web browsing and email checking. It's possible--I've done it on similar DOS machines--but it's complicated.
I also had a parallel-port-based ethernet adapter that could work, but that too would take lots of configuration time. Above all else, the most limiting factor for this method was the fact that most of the DOS-based Internet software I found (including the smallest text-based Web browser) could not fit on a 360KB disk.
So I decided to try the easiest solution: I could use the 5150's serial port as an umbilical to a more modern PC that would act as a vintage ISP server. I happened to have just such a machine, running Linux, already set up (I use it to test my vintage serial terminals). Linux, like its Unix ancestors, can redirect its text-based command prompt (similar to the command line in MS-DOS) to a serial port on its host machine. In this scenario, I would connect the 5150 to the Linux computer with a serial cable, and the 5150 would run a special piece of software called a terminal emulator. That software allows the 5150 to act as a fancy monitor and keyboard for the Linux machine.
This approach may seem like cheating, but it is exactly how people from the 5150 era all the way up to the early 1990s used the Internet and other networks. They dialed up, logged in, and ran software on the remote machine, receiving results from the remote network through a telephone modem connection. In my case, no dialing up would be necessary because the two computers were sitting a few feet from each other.
You've Got Mail
After linking the 5150 to my pseudo-ISP machine, I booted up and ran DataStorm's Procomm Plus, a very popular shareware terminal-emulator program from the 1980s. I logged in to the Linux system and ran Pine, a program that Linux folks may remember as the most popular way to check Internet email before graphical OSs and PPP connections shifted things over to client-side software like Eudora.
It worked. Sadly, I had no new email. Testing the IBM's email functionality would not be complete without sending an email message, so I fired a note off to one of my colleagues.