Spam is the email equivalent of junk mail or nuisance phone calls. Spam can simply be defined as all unsolicited electronic mail sent out in bulk to individuals/organizations that have not consented to receive it.
Spam has a number of different classifications:
- Unsolicited Commercial Email (UCE) which usually advertises a product or service.
- Chain letters and pyramid schemes.
- Messages sent to a recipient who had agreed to receive mail but has subsequently opted-out.
- Any email without an Opt-out facility.
- Any email that does not have a valid address in the reply to line.
Some SPAM offers are fraudulent; it is safest to not do business with spammers.
Be careful clicking on links in SPAM email. Some of these links are designed to capture personal information or download malicious software to your computer without you knowing it.
Opt'ing Out ... By selecting the opt-out option on an email you may be confirming your email address is valid leading to spammers sending you even more SPAM email.
Never respond to SPAM messages. Forward SPAM messages to the FTC (firstname.lastname@example.org) and your ISP (internet service provider), do not open them if possible and delete these messages after forwarding them.
Decide if you want to use two email addresses, one for personal messages and one for newsgroups, chat rooms, etc.
Avoid listing your primary email address in public places like newsgroups, chat rooms, web sites, or membership directories.
A great source for more information: http://www.ftc.gov/bcp/conline/edcams/spam/consumer.htm