The common term for unsolicited bulk email is Spam. It describes unwanted messages sent to large numbers of recipients, often for advertising, scams, or malware distribution.
The word’s internet meaning comes from a 1970 Monty Python television sketch in which characters repeatedly sing about SPAM, the canned meat product. The relentless repetition became a fitting metaphor for intrusive messages that keep appearing in inboxes. The first widely recognized email spam campaign was sent by Gary Thuerk in 1978 to about 600 people on ARPANET.
Spam and phishing are related but not identical. Spam is defined mainly by being unsolicited and sent in bulk; phishing is an attempt to trick someone into revealing information or clicking a harmful link. A spam message may contain phishing, malware, or ordinary marketing content.
Modern email systems use filters, reputation lists, authentication checks, and content analysis to identify spam. Even legitimate companies can create spam-like messages if they email people without meaningful consent or make unsubscribing difficult.