Editing Open proxy (section)

==Testing for access from an open proxy==
Because open proxies are often implicated in abuse, a number of methods have been developed to detect them and to refuse service to them. [[IRC]] networks with strict usage policies automatically test client systems for known types of open proxies.<ref>{{cite web |url= http://www.bestvpnservicemag.com/blitzed-open-proxy-monitor-bopm-version-2-3/ |title= Blitzed Open Proxy Monitor |publisher= Blitzed.org |date= 2011-08-21 |access-date= June 21, 2014 |url-status= dead |archive-url= https://web.archive.org/web/20140815234109/http://www.bestvpnservicemag.com/blitzed-open-proxy-monitor-bopm-version-2-3/ |archive-date= August 15, 2014 }}</ref> Likewise, a [[mail transport agent|mail server]] may be configured to automatically test mail senders for open proxies, using [[software]] such as proxycheck.<ref>{{cite web|url= http://www.corpit.ru/mjt/proxycheck.html |title= proxycheck: Open Proxy checker |publisher= Corpit.ru |access-date= 2011-11-21 }}</ref>

Groups of IRC and electronic mail operators run [[DNSBL]]s publishing lists of the [[IP address]]es of known open proxies, such as [[AHBL]], [[Composite Blocking List|CBL]], [[NJABL]] (till 2013), and [[SORBS]] (in operation since 2002). The AHBL discontinued public access in 2015.<ref>{{cite web|url=https://www.ahbl.org/|title=Official Abusive Hosts Blocking List Website}}</ref>