Definition of spam in The Network Encyclopedia.

What is SPAM?

Unsolicited e-mail such as chain letters and advertising for services or products. To avoid getting spam, you can do the following:

  • Avoid posting messages to Usenet newsgroups.
  • Never reply to junk mail.
  • Configure filters on your mail client to filter out mail containing certain keywords.
  • Ask your Internet service provider (ISP) to configure its mail servers to reject spam.

Spam is sometimes politely referred to as unsolicited commercial e-mail (UCE).


To prevent abuse by spammers, the SMTP service of Internet Information Server (IIS) version 4 by default does not allow Simple Mail Transfer Protocol (SMTP) mail to be relayed through it to an outside e-mail address.


If your e-mail address somehow gets on the mailing lists of spammers, you can usually configure rules on your e-mail program’s Inbox to discard mail that comes from a specific address, uses words such as “sale” or “buy” in the subject header, or has specific words or phrases in the body of the message, but this is usually a tedious and losing game. A better solution is to use the Delete key. If the situation gets really bad, see whether your mail administrator or ISP can filter out spam.