Editing Email spam (section)

{{Short description|Unsolicited messages sent by email}}
[[Image:spammed-mail-folder.png|thumb|300px|An [[email box]] folder filled with spam messages.]]
'''Email spam''', also referred to as '''junk email''', '''spam mail''', or simply '''spam''', refers to unsolicited messages sent in bulk via [[email]]. The term originates from a [[Spam (Monty Python)|Monty Python sketch]], where the name of a canned meat product, "[[Spam (food)|Spam]]," is used repetitively, mirroring the intrusive nature of unwanted emails.<ref name=DfnSpam>{{cite dictionary|url=http://www.merriam-webster.com/dictionary/spam|dictionary=[[Merriam-Webster Dictionary]]|title=spam}}</ref> Since the early 1990s, spam has grown significantly, with estimates suggesting that by 2014, it comprised around 90% of all global email traffic.<ref name="MAAWG.org">{{cite web|date=November 2014 |url=http://www.maawg.org/email_metrics_report
|access-date=3 November 2017|archive-date=2015-04-03
|archive-url=https://web.archive.org/web/20150403181626/https://www.m3aawg.org/email_and_bot_metrics_report|url-status=live
|title=M{{sup|3}}AAWG Email Metrics Program: The Network Operators' Perspective; Report #16 – 1st Quarter 2012 through 2nd Quarter 2014
|publisher=Messaging, Malware and Mobile Anti-Abuse Working Group (M{{sup|3}}AAWG)}}</ref><ref name=JNCA-2014>{{Cite journal |last1=Fu |first1=JuiHsi |last2=Lin |first2=PoChing |last3=Lee |first3=SingLing |date=2014-08-01 |title=Detecting spamming activities in a campus network using incremental learning |url=https://www.sciencedirect.com/science/article/pii/S1084804514000630 |journal=Journal of Network and Computer Applications |language=en |volume=43 |pages=56–65 |doi=10.1016/j.jnca.2014.03.010
|issn=1084-8045 |access-date=2022-10-30 |archive-date=2020-04-30
|archive-url=https://web.archive.org/web/20200430111059/https://www.sciencedirect.com/science/article/pii/S1084804514000630
|url-status=live |url-access=subscription }}</ref>

Spam is primarily a financial burden for the recipient, who may be required to manage, filter, or delete these unwanted messages. Since the expense of spam is mostly borne by the recipient,<ref name="spam-costs">{{cite web|url=http://www.clickz.com/showPage.html?page=1432751|title=Make Spammers Pay Before You Do|publisher=The ClickZ Network|first=Rebecca |last=Lieb|date=July 26, 2002
|access-date=2010-09-23|archive-url=https://web.archive.org/web/20070807113021/http://www.clickz.com/showPage.html?page=1432751|archive-date=2007-08-07}}</ref> it is effectively a form of "[[postage due]]" [[advertising]],<ref name=IRJETS-2023>{{cite journal|accessdate=February 24, 2025
|url=https://www.irjmets.com/uploadedfiles/paper//issue_10_october_2023/45571/final/fin_irjmets1698428185.pdf|format=pdf
|title=Spam email classifier
|first1=Shraddha |last1=Sharma |first2=Meenal D. |last2=Amritphale |first3=Krish |last3=Vijayvargiya
|first4=Harshwardhan |last4=Akhand |first5=Jinisha |last5=Kataria
|journal=International Research Journal of Modernization in Engineering Technology and Science |volume=05|number=10 |date=October 2023 |pages=2365–2369
|quote=Spam is effectively [[postage due]] [[advertising]] because the recipient bears the majority of the cost.}}</ref> where the recipient bears the cost of unsolicited messages. This cost imposed on recipients, without compensation from the sender, makes spam an example of a "[[negative externality]]" (a side effect of an activity that affects others who are not involved in the decision).<ref name=EconSpam2012>{{citation|title=Economics of Spam|journal=Journal of Economic Perspectives|volume=26|issue=3|pages=87–110|doi=10.1257/jep.26.3.87|year=2012|last1=Rao|first1=Justin M.|last2=Reiley|first2=David H.|doi-access=free}}</ref>

The legal definition and status of spam varies from one jurisdiction to another, but laws and lawsuits have not generally been successful in stemming spam.<ref>{{Cite news |date=2024-08-19 |title=Email Unsubscribe Services Don't Really Work. Follow This (Free) Advice Instead. |url=https://www.nytimes.com/wirecutter/reviews/best-email-unsubscribe-service/ |access-date=2025-03-06 |work=The New York Times |language=en-US |issn=0362-4331}}</ref>

Most email spam messages are commercial in nature. Whether commercial or not, many are not only annoying as a form of [[attention theft]], but also dangerous because they may contain [[Html email#Security vulnerabilities|links]] that lead to [[phishing]] web sites or sites that are hosting [[malware]] or include malware as file [[email attachment|attachments]].

Spammers collect email addresses from chat rooms, websites, customer lists, newsgroups, and viruses that harvest users' address books. These collected email addresses are sometimes also sold to other spammers.