Editing Domain Name System blocklist (section)

== Criticism ==
Some end-users and organizations have concerns regarding the concept of DNSBLs or the specifics of how they are created and used.  Some of the criticisms include:
* Legitimate emails blocked along with spam from shared mailservers. When an ISP's shared mailserver has one or more compromised machines sending spam, it can become listed on a DNSBL. End-users assigned to that same shared mailserver may find their emails blocked by receiving mailservers using such a DNSBL.<ref>{{cite web |url=http://www.topwebhosts.org/articles/email-delivery-problems.php |title=Email delivery problems explained |access-date=2013-03-26}}</ref> In May 2016, the SORBS system was blocking the SMTP servers of Telstra Australia, Australia's largest internet service provider. This is no surprise as at any one time, there would be thousands of computers connected to this mail server infected by zombie type viruses sending spam. The effect is to cut off all the legitimate emails from the users of the Telstra Australia system.
* Lists of dynamic IP addresses. This type of DNSBL lists IP addresses submitted by ISPs as dynamic and therefore presumably unsuitable to send email directly;<ref name="EFF-Effector"/> the end-user is supposed to use the ISP's mailserver for all sending of email.  But these lists can also accidentally include static addresses, which may be legitimately used by small-business owners or other end-users to host small email servers.<ref>{{cite web |url=http://www.spamhaus.org/pbl/ | title=The Spamhaus Project, Policy Block List |access-date=2013-03-26}}</ref>
* Lists that include "spam-support operations", such as MAPS RBL.<ref>{{cite web|url=http://www.mail-abuse.com/ |title=Maps Rbl |publisher=Mail-abuse.com |date=2012-03-03 |access-date=2012-05-06}}</ref> A spam-support operation is a site that may not directly send spam, but provides commercial services for spammers, such as hosting of Web sites that are advertised in spam. Refusal to accept mail from spam-support operations is intended as a [[boycott]] to encourage such sites to cease doing business with spammers, at the expense of inconveniencing non-spammers who use the same site as spammers.
* Some lists have unclear listing criteria and delisting may not happen automatically nor quickly. A few DNSBL operators will request payment (e.g. uceprotect.net)<ref>{{cite web |author=UCEPROTECT |url=http://www.uceprotect.net/en/index.php?m=2&s=0 |title=UCEprotect.net |publisher=UCEprotect.net |access-date=2012-05-06}}</ref> or donation (e.g. [[SORBS]]). Some of the many listing/delisting policies can be found in the Comparison of DNS blacklists article.
* Because lists have varying methods for adding IP addresses and/or URIs, it can be difficult for senders to configure their systems appropriately to avoid becoming listed on a DNSBL. For example, the UCEProtect DNSBL seems to list IP addresses merely once they have validated a recipient address or established a TCP connection, even if no spam message is ever delivered.<ref name="mailchannels-blog-1">{{cite web |author-last=Simpson |author-first=Ken |title=Getting onto a blacklist without sending any spam |url=http://mailchannels.com/blog/2010/11/getting-off-of-blacklists-uceprotect-in-particular/ |work=MailChannels Blog |publisher=MailChannels Corporation |access-date=2011-09-16 |archive-url=https://web.archive.org/web/20110919025707/http://mailchannels.com/blog/2010/11/getting-off-of-blacklists-uceprotect-in-particular/ |archive-date=2011-09-19 |url-status=dead }}</ref>

Despite the criticisms, few people object to the principle that mail-receiving sites should be able to reject undesired mail systematically. One person who does is [[John Gilmore (activist)|John Gilmore]], who deliberately operates an [[open mail relay]]. Gilmore accuses DNSBL operators of violating [[antitrust]] law.

{{blockquote|For Joe Blow to refuse emails is legal (though it's bad policy, akin to "shooting the messenger"). But if Joe and ten million friends all gang up to make a blacklist, they are exercising illegal monopoly power.<ref>{{cite web |url=http://www.toad.com/gnu/verio-censorship.html |title=TOAD.com |publisher=TOAD.com |access-date=2012-05-06 |archive-url=https://web.archive.org/web/20120503021816/http://www.toad.com/gnu/verio-censorship.html |archive-date=2012-05-03 |url-status=dead }}</ref>}}

A number of parties, such as the [[Electronic Frontier Foundation]] and [[Peacefire]], have raised concerns about some use of DNSBLs by [[Internet service provider|ISP]]s. One joint statement issued by a group including EFF and Peacefire addressed "stealth blocking", in which ISPs use DNSBLs or other spam-blocking techniques without informing their clients.<ref>{{cite web |url=http://www.peacefire.org/stealth/group-statement.5-17-2001.html |title=Coalition statement against "stealth blocking" |publisher=Peacefire.org |date=2001-05-17 |access-date=2012-05-06}}</ref>

=== Lawsuits ===
Spammers have pursued lawsuits against DNSBL operators on similar grounds:
* In 2003, EMarketersAmerica.org filed a lawsuit against a number of DNSBL operators in a [[United States District Court for the Southern District of Florida|Florida court]]. Backed by spammer [[Eddy Marin]], the company claimed to be a trade organization for [[Email marketing|email marketers]] and that DNSBL operators [[The Spamhaus Project|Spamhaus]] and SPEWS were engaged in [[restraint of trade]]. The suit was eventually dismissed for lack of [[standing (law)|standing]].<ref name="wired">{{cite magazine |last1=McWilliams |first1=Brian |title=No Truce in the Spam Wars |url=https://www.wired.com/2003/09/no-truce-in-the-spam-wars/ |access-date=12 April 2021 |magazine=Wired |date=10 September 2003}}</ref><ref>{{cite web |url=http://www.linxnet.com/misc/spam/slapp.php |title=Linxnet.com |publisher=Linxnet.com |access-date=2012-05-06}}</ref>
* In 2006, a U.S. court ordered Spamhaus to pay $11.7 million in damages to the spammer e360 Insight LLC. The order was a [[default judgment]], as Spamhaus, which is based in the UK, had refused to recognize the court's [[jurisdiction]] and did not defend itself in the [[The Spamhaus Project#e360 lawsuit|e360 lawsuit]]. In 2011, his decision was overturned by the [[Seventh Circuit Court of Appeals|United States Court of Appeals for the Seventh Circuit]].<ref name="register">{{cite news |last1=Leyden |first1=John |title=Spamhaus victorious after 5-year fight with mass mailer |url=https://www.theregister.com/2011/09/05/spamhaus_e360_insight_lawsuit/ |access-date=12 April 2021 |work=The Register |date=5 September 2011}}</ref>