Editing Open mail relay (section)

{{Short description|SMTP server that allows anyone to send e-mail through it}}
[[File:Email.svg|thumb|Mail relay diagram]]
An '''open mail relay''' is a [[Simple Mail Transfer Protocol]] (SMTP) [[Server (computing)|server]] configured in such a way that it allows anyone on the [[Internet]] to send [[Email|e-mail]] through it, not just mail destined to or originating from known users.<ref name="iukb">{{Cite web |url=http://www.kb.indiana.edu/data/aivh.html |title=In Unix, what is an open mail relay? |access-date=2008-04-07 |last=The Trustees of Indiana University |date=2008-04-01 |work=University Information Technology Services |publisher=[[Indiana University]] |archive-url=https://web.archive.org/web/20070617083024/http://kb.iu.edu/data/aivh.html |archive-date=2007-06-17 |url-status=dead }}</ref><ref name="whatis">{{Cite web|url=http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci782509,00.html |title=What is open relay? |access-date=2008-04-07 |date=2004-07-19 |work=WhatIs.com |publisher=[[Indiana University]] |archive-url=https://web.archive.org/web/20070824005337/http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci782509,00.html |archive-date=2007-08-24}}</ref><ref>{{Cite web|url=http://www.ftc.gov/opa/2004/01/opsecure.shtm |title=FTC and International Agencies Announce "Operation Secure Your Server" |access-date=2008-04-07 |date=2004-01-29 |publisher=[[Federal Trade Commission]] |url-status=dead |archive-url=https://web.archive.org/web/20080306235101/http://www.ftc.gov/opa/2004/01/opsecure.shtm |archive-date=March 6, 2008}}</ref> This used to be the default configuration in many mail servers; indeed, it was the way the Internet was initially set up, but open mail relays have become unpopular because of their exploitation by [[Spamming|spammers]] and [[computer worm|worms]]. Many relays were closed, or were placed on [[blacklist (computing)|blacklist]]s by other servers.