The first recognisable e-mail marketing message was sent on 3 May, 1978 to 400 people on behalf of DEC - a now-defunct computer-maker.
The message was sent via Arpanet - the internet's forerunner - and won its sender much criticism from recipients.
Thirty years on, spam has grown into an underground industry that sends out billions of messages every day.
Statistics gathered by the FBI suggest that 75% of net scams snare people through junk e-mail. In 2007 these cons netted criminals more than $239m (£121m).
Statistics suggest that more than 80%-85% of all e-mail is spam or junk and more than 100 billion spam messages are sent every day.
The majority of these messages are being sent via hijacked home computers that have been compromised by a computer vi
