It's funny to see people who know the word 'SPAM' as 'unsolicited email' find out that this is not the original meaning of the word.

There's supposed to be a scetch in Monty Python's Flying Circus (I never saw it myself, unfortunately) with some guys that keep singing SPAM, SPAM, SPAM all the time, and unsolicited. Very much like the SPAM mails we receive today. Someone – a fan of the show, no doubt – saw the similarity, and gave UCE the name we mostly use today. The company that makes SPAM doesn't mind, apparently – although it insists it has nothing to do with unsolicited email. Naturally.