O.K., it probably is too late, but:

I was out this morning walking my dog, and noticed (again) that he was "marking" all over. It's fairly common around here to call a dog's little urine markings "p-mail," and it occurred to me that a more descriptive name for unsolicited e-mail might, by extension, also be "p-mail."

P.S. for non-US English speakers: In the USA the act of urination is referred to colloquially as "peeing," and urine is referred to as "pee." Also in the US, urine is considered an undesirable human waste product, and mention of it is not considered to be "polite."

Spam was the only meat available to the UK during WWII and general dislike for it prompted (in a roundabout way) the Monty Python "Spam" sketch/song. Spam, in the sketch, was forced on the buyers and was unwanted and ended up filling the entire sketch (vocally, at least).

Spam stays.