In 1990 I was running a very tiny Unix clone at home (Coherent on a 286 PC w/ 1 meg ram) and… I don’t remember if I couldn’t get a standard reader to compile on that or what the problem was, but anyways - I wrote an email/usenet reader for my own use.
33 years later, I’m still using it to read my email every day.
Also, I think I’ve had my pasta strainer since the 90s.
An email of all html is an unwanted email 99% of the time. Occasionally, I save it, and open in lynx. (When a web site emails a security code.)
Attachments are more of a hassle, because I frequently need those. Save to a temp file, “munpack file”, examine extracted files.