Though not an acronym, SPAM does stand for something.
To most users, SPAM stands for "annoyance," and for many users, "theft." In truth, SPAM is unsolicited email, usually commercial, delivered in bulk to a large number of users.
SPAM, in addition to being unsolicited, has other problems. It wastes Internet bandwidth, because the same message is delivered to vast numbers of Internet users.
It costs money for unwilling recipients who pay for Internet access, because they must download the email unnecessarily. Finally, it wastes computational time delivering the mail, and the storage
space to hold it.
A spammer is anyone who sends SPAM. Spammers compile their mailing lists in a variety of ways; sometimes they purchase lists, but more often they simply harvest email addresses from Web sites and newsgroups.
Spammers import their email address lists into bulk mailing software. This software is able to deliver vast quantities of email extremely rapidly, often through short-term, free email accounts. They repeat this process hundreds of times a day,
and as you might suspect, the number of emails they send grows enormously.
Often spammers will forge their email headers so their mailings appear to come from other sources.
If the recipients retaliate, for example by complaining to their ISP, innocent sites might be held responsible for the spammers' actions.
Spammers who are more ethical use an "opt-in" methodology: rather than receiving an email out of nowhere, you must first request it.
The next lesson lists methods to combat SPAM.