This was the first commercial spam, and it took place in 1978. That year DEC announced a new computer entitled DEC-20. As an extension to their marketing campaign, they got a hold of great number of ARPANET addresses from the people situated on the west coast of United States of America, and sent their marketing brochure to all those addresses they had. Finally, ARPANET saw this as an offence of their policy and a message was sent out, to remind people that this is not the way and that it won't be tolerated in the future.

As I read few of the old spam related threads, there is a transcript that shows that even young Richard Stallman was defending spam in his reactions to DEC spam.

3) jj@cup.portal.com spam

This spam is noted as the first spam that hit the USENET groups. About 14 years ago (24.05.1988) Rob Noha, using the account JJ@cup.portal.com sent a message titled "HELP ME!" to a great number of available news groups. Thanks to Google, his message can be still read online:

"Hi. I just finished my junior year in college, and now I'm faced with a major problem. I can't afford to pay for my senior year. I've tried everything. I can't get any more student loans, I don't qualify for any more scholarships, and my parents are as broke as am I. So as you can see, I've got a major problem. But as far as I can see, there is only one solution, to go forward. I've come along way, and there is no chance in hell that I'm going to drop out now! I'm not a quiter, and I'm not going to give up. "

4) March 30 ARMM Massacre

Richard E. Depew is according to Wired's article, regarded as Usenet's major bincanceler (for removing binary files from nonbinary newsgroups) was connected with 1993 ARMM spam. He advanced the idea of semi-moderating the USENET groups, cancelling some posts that weren't written according to the rules. He developed a software, which main purpose was to help him do the moderation. Then something went wrong - his ARMM tool had a bug, so when he started it it sent couple hundreds of messages to the "appropriate" news.admin.policy news group. As Brad Templeton noted - "The very day ARMM was run, Joel Furr, as far as I can tell, was the first to call a spam a spam".

This was a trip to the memory lane for someone, and just a bunch of boring or interesting facts for others. Brad Templeton did a great research on Spam Etymology, and his study is the main reference for the mentioned moments in spam history. Keith Lynch runs a great spam related timeline, and the whole list can be found in the References section. You can learn lot of interesting information from the timeline:

June 1995 - Two coined words appeared - spamvertise (to advertise via spam) and spamware (spamming software)
August 1995 - List of 2 million email addresses is offered for sale
October 1995 - Mailboxes for abuse related contacts are opening (abuse@provider)
June 1997 - FTC spam hearing (more information)
July 1997 - news.admin.net-abuse.email starts with its work