The first spam message was sent to 393 users of ARPANET on May 2 1978 by someone from computing pioneers DEC. They had to type in all the addresses by hand first." It was Gary Thuerk who sent a marketing pitch for a new computer model from his employer, Digital Equipment Corporation

Brad Templeton of the Electronic Frontier Foundation actually has it archived. You can see the entire mail, plus the reactions it generated on this site.

http://www.templetons.com/brad/spamreact.html#msg

-Dennis
Eloqua