No, not the junk email… the meat product from Hormel. According to a recent issue of the Straight Dope:
The common assumption is that Spam is made of stuff even pigs don’t like to admit they’ve got. Not so, says a spokeswoman for Hormel Foods, which manufactures Spam. It contains a mixture of ham and chopped pork shoulder. (Ham is the pig’s thigh; pork is everything else.) Ham is Hormel’s top-of-the-line product, and Spam was created in 1937 partly to use up what was left of the pig after the ham had been removed. But only the wholesome parts.