With letters I'm unsure of, in webmail I right click and save the mail as text, .txt, and then read that in something like Notepad, where nothing can execute.
Jack Jones' mailing is legit, it seems to be just a pirate name, and the site is real, and it's a nice little site. I wrote back and suggested that some of the valves he's using in the transmitter might be harder to find for USA builders, but I like the straightforward circuits and how he built them.
I've worked with that hybrid style of transmitter, with tube finals but with a solid state modulator. It can give better sound over push-pull tubes because it has only the modulation transformer, and can benefit from transistor amps' tight negative feedback for a flatter response.
I also noted that he's used an audio bandpass filter in his higher power rigs, which it seems American stations rarely use. It's a fairly strong filter too.
Boomer