Chain letters have been a around since at least 1885, according to research by Daniel W. VanArsdale. Chain letters are letters that experience exponential growth by asking the recipient to send out multiple copies to other people and also ask that this chain of distribution not be broken.
If you didn't send out a bulk e-mail campaign in the middle of the night but checked your inbox in the morning and found a lot of bounce messages with the subject lines like "failure notice", "Delivery Status Notification (Failure)", "Mail delivery failed: returning message to sender", "Undeliverable mail:", etc., you may have a virus.
"What is the purpose of spam?" This is often the first question asked in any discussion about unwanted e-mails. This article is going to briefly discuss what fuels the continuing onslaught of unsolicited commercial e-mail.