Netiquette Rule #6: Do not spam

Do not spam or follow pop-up and spam links because they can lead to viruses, spyware, and malware.

Spam, in terms of security, is an automatically generated email sent to a bulk list of email addresses. Any unsolicited email is spam, but the ones that pose the most risk are automatically generated ones to bulk address lists.

Do not click links in unsolicited email or download attachments. Delete all email from unknown sources because it may lead to a virus. Therefore, it is proper netiquette to refrain from using spam as a cheap advertising technique or tactic because it puts computers at risk through its use. The more spam there is the more of security threat it is for everyone.

(Source: Netiquette Rule #6: Do not spam)