DNS Blacklist Monitoring \u2014 Know You’re Listed Before Your Email Stops Arriving<\/h1>\n
Blacklisting is silent.<\/strong> Mail is rejected at the receiving server, so nothing looks wrong from your side. Dotcom-Monitor checks your IPs and domains against 70+ DNSBLs continuously and tells you which list flagged you, within minutes. 10,000+<\/p>\n Organizations Worldwide<\/p>\n 99.99%<\/p>\n Platform Uptime SLA<\/p>\n 30+<\/p>\n Global Monitoring Locations<\/p>\n Since 1998<\/p>\n Website Monitoring Leader<\/p>\n A DNS blacklist (DNSBL)<\/strong>, also called a DNS blackhole list or real-time blackhole list (RBL), is a published database of IP addresses and domains flagged for sending spam, distributing malware, or other abusive activity. Mail servers query these lists in real time before accepting a message: if your sending IP appears on a list the receiving server trusts, your email is rejected or routed to spam before it ever reaches the recipient.<\/p>\n Listings happen for reasons that are often outside your control \u2014 a compromised mailbox on your network, a misconfigured relay, a shared-hosting neighbor’s behavior, or a recycled IP address that carries a prior owner’s reputation. Because each blacklist operates independently with its own criteria and delisting process, an organization can be listed on one and clean on a dozen others, which is why point-in-time checks are unreliable and continuous monitoring matters.<\/p>\n Need a one-time check right now? Run a free email blacklist test<\/a> on Dotcom-Tools \u2014 no account required.<\/p>\n How it works<\/p>\n A DNSBL task polls the major blacklist databases for any IP or hostname you specify, on the interval you choose.<\/p>\n 1<\/p>\n Enter the hostname or IP address to watch \u2014 typically your outbound mail servers, marketing sending IPs, and root domain.<\/p>\n 2<\/p>\n Each check queries the major DNSBL databases and compares the response against a clean baseline.<\/p>\n 3<\/p>\n A positive match on any list raises an error and records which list flagged you, and when \u2014 the detail every delisting request asks for.<\/p>\n 4<\/p>\n A blacklist listing is an email-deliverability incident. Send it to whoever owns mail, not only to the on-call SRE.<\/p>\n 5<\/p>\n Continuous re-checks show when the listing clears across lists \u2014 and catch the re-listing that follows a partial fix.<\/p>\n Coverage<\/p>\n Each list runs independently, with its own listing criteria and its own removal process. Being clean on one says nothing about the others \u2014 which is the whole argument for checking all of them continuously.<\/p>\n The most widely deployed set of lists. SBL covers verified spam sources, XBL lists compromised or exploited machines, PBL covers IP ranges that should not be sending mail directly, and DBL is domain-based. A Spamhaus listing has the broadest deliverability impact of any blacklist.<\/p>\n Built from user-submitted spam reports and spamtrap hits. Listings expire automatically roughly 24 hours after reports stop, which makes SCBL a fast-moving signal \u2014 you can be listed and delisted inside a day without ever noticing.<\/p>\n A reputation-scored list used widely by Barracuda appliances in corporate mail environments. Lookups are free, with registration required for high-volume querying. Common cause of B2B mail being silently rejected.<\/p>\n Operates in tiers: Level 1 lists a single IP, Level 2 an entire subnet, Level 3 a whole ASN. Levels 2 and 3 are why a well-behaved sender on shared hosting can be blocked because of a neighbor’s behavior.<\/p>\n Spamtrap-driven, with automatic expiry rather than manual review. Listings clear on their own once the offending traffic stops, but recurring listings are a reliable signal that a root cause was never actually fixed.<\/p>\n URI-based rather than IP-based: they list domains that appear inside<\/em> message bodies. A listing can therefore follow your domain even in mail you did not send \u2014 spam that merely links to your website is enough to trigger it.<\/p>\n Remediation<\/p>\n Delisting is not the hard part \u2014 staying delisted is. Lists re-flag an address quickly when the underlying cause was only partly addressed, so work the steps in order.<\/p>\n 01<\/p>\n Check the specific IP or domain against each major DNSBL and note the listing reason code the list provides. Different lists mean different root causes.<\/p>\n 02<\/p>\n Common causes: a compromised account sending spam, an open relay or open proxy, malware on a machine behind the IP, a misconfigured mail server, or missing and incorrect SPF, DKIM, and DMARC records.<\/p>\n 03<\/p>\n Publish valid SPF, DKIM, and DMARC records before<\/em> requesting removal. Most lists will re-list an IP that was delisted while the underlying problem remained.<\/p>\n 04<\/p>\n Each blacklist has its own form and policy. Some \u2014 SpamCop, PSBL \u2014 expire listings automatically. Others, such as Spamhaus SBL, require a manual request explaining what you remediated.<\/p>\n 05<\/p>\n Removal can take from a few hours to several days to reach all mail servers, because receiving servers cache DNSBL responses rather than querying live every time.<\/p>\n 06<\/p>\n Re-listing is common when the root cause was only partly fixed. Automated monitoring catches a repeat listing in minutes, instead of when customers report undelivered mail.<\/p>\n Capabilities<\/p>\n Get notified the moment a monitored IP or domain appears on any tracked list \u2014 email, SMS, Slack, PagerDuty, or webhook.<\/p>\n Every alert names the specific list, the listing time, and the reason code \u2014 the exact information each delisting process requires.<\/p>\n Reach the right DNSBL quickly with the listing evidence already assembled, instead of hunting for each list’s removal form.<\/p>\n Confirm a removal genuinely propagated, and catch the re-listing that follows a partial fix \u2014 a pattern manual checks always miss.<\/p>\n Route deliverability incidents to whoever owns mail, with escalation rules separate from your infrastructure alerts.<\/p>\n Pull blacklist status into your own dashboards, or push events into the incident tooling your team already runs.<\/p>\n A blacklist listing rarely reaches the team that can fix it. It looks like an infrastructure alert, but the remediation is a mail-configuration and reputation problem.<\/p>\n Who uses it<\/p>\n Password resets and order confirmations are the mail customers notice missing first \u2014 and the mail that generates support tickets and churn when it silently disappears into a reject queue.<\/p>\n A listing mid-campaign quietly destroys deliverability metrics and can get a sending domain throttled for weeks after the underlying issue is resolved.<\/p>\n Tiered lists can flag an entire subnet or ASN because of another tenant. Monitoring tells you it happened to you, rather than leaving you to infer it from falling open rates.<\/p>\n DNSBL monitoring is part of the Internet Infrastructure plan \u2014 the same plan that covers DNS, port, ping, and traceroute monitoring.<\/p>\n Starts at Verified reviews from Capterra. Aggregate rating 4.5 \/ 5 across 83 reviews.<\/p>\n I have been thoroughly impressed with the level of detail and comprehensiveness of the reports generated by the software. The support team has exceeded my expectations \u2014 they consistently provide detailed and insightful answers to every question.Shirin R.Software Test Engineer \u00b7 Computer SoftwareVerified Capterra review \u00b7 February 2023 4.5<\/strong><\/p>\n Capterra<\/p>\n83 reviews<\/p>\n 4.6<\/strong><\/p>\n Ease of Use 4.6<\/strong><\/p>\n Customer Service All reviews sourced from Capterra verified reviews<\/a>. Ratings as of 8\u6708 2026.<\/em><\/p>\n Frequently asked questions<\/p>\n If your question isn’t covered here, our team responds within one business hour.<\/p>\n A DNS blacklist (DNSBL), also called a DNS blackhole list or real-time blackhole list (RBL), is a published database of IP addresses and domains flagged for sending spam, distributing malware, or other abusive activity. Mail servers query these lists in real time before accepting a message, and reject or spam-folder mail from any address that appears on a list they trust.<\/p>\n You specify the IP addresses or hostnames you want watched. Dotcom-Monitor then polls 70+ public DNSBL databases on your chosen interval and compares the result to a clean baseline. If any list returns a positive match, the check is flagged as an error, the responsible list is identified, and an alert is dispatched to your team.<\/p>\n Blacklisting is silent. Mail is rejected at the receiving server, so nothing looks wrong from your side \u2014 no bounce you notice, no alarm in your infrastructure. Most teams discover a listing only when a customer says an invoice, receipt, or password reset never arrived, by which point days of mail may already be lost.<\/p>\n Beyond detection, Dotcom-Monitor reports which specific list flagged you and when the listing appeared, which narrows the root cause quickly. That detail is what each blacklist\u2019s delisting process asks for, and continuous re-checks confirm when removal has actually propagated rather than leaving you to guess.<\/p>\n It varies by list. Some, such as SpamCop and PSBL, expire listings automatically within roughly 24 hours once the abusive traffic stops. Others require a manual delisting request and can take several days. After removal, allow extra time for receiving mail servers to refresh their cached DNSBL results.<\/p>\n Listings are frequently caused by something other than deliberate spam: a single compromised mailbox, a misconfigured relay or open proxy, malware on one machine behind the IP, or a recycled IP that still carries its previous owner\u2019s reputation. On shared hosting, tiered lists such as UCEPROTECT can list an entire subnet because of a neighbor\u2019s behavior.<\/p>\n Continuously, not periodically. A manual check tells you only about the moment you ran it, and a listing can appear hours later. For any address that sends transactional or marketing mail, automated checks at short intervals mean you learn about a listing in minutes rather than when customers report missing email.<\/p>\n IP-based lists such as Spamhaus SBL and Barracuda BRBL flag the sending server\u2019s address. Domain and URI-based lists such as Spamhaus DBL, SURBL, and URIBL flag domains that appear inside the message body. That difference matters because a URI listing can follow your domain even in mail you did not send, such as spam that merely links to your site.<\/p>\n Setting up your first check? See the DNSBL task setup guide<\/a>, or compare with DNS monitoring<\/a>.<\/p>\n Set up a DNSBL check in under five minutes. 70+ blacklists, continuous polling, alerts routed to the team that owns mail.<\/p>\n
\n
\nStart 30-Day Free Trial
\n<\/a>
\n
\nSee Pricing
\n<\/a>
\n![\"DNSBL](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/dns-blacklist-monitoring-hero.webp\")
<\/p>\n\n
![\"Aflac](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/aflac_logo-1.png\"){kind=logo}
\n![\"Dell](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/dell_logo-1.png\" "\\"dell_logo\\""){kind=logo}
\n![\"Comcast](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/comcast_logo-1.png\" "\\"comcast_logo\\""){kind=logo}
\n![\"dish_logo\"](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/dish_logo-1.png\" "\\"dish_logo\\""){kind=logo}
\n![\"citrix_logo\"](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/citrix_logo-1.png\" "\\"citrix_logo\\""){kind=logo}
\n![\"xerox\"](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/xerox-logo-grey.png\" "\\"xerox-logo-grey\\""){kind=logo}
\n![\"volvo\"](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/volvo-logo-grey.png\" "\\"volvo-logo-grey\\""){kind=logo}
\nDNS Blacklist Monitoring<\/p>\nWhat Is a DNS Blacklist (DNSBL)?<\/h2>\n
From Listing to Alert in Minutes, Not Days<\/h2>\n
Specify the target<\/h3>\n
Poll 70+ blacklists on a schedule<\/h3>\n
Flag the listing and name the list<\/h3>\n
Route the alert to the right team<\/h3>\n
Confirm removal actually propagated<\/h3>\n
Major DNS Blacklists We Monitor<\/h2>\n
\n
Spamhaus (SBL, XBL, PBL, DBL)<\/h3>\n
\n
SpamCop Blocking List (SCBL)<\/h3>\n
\n
Barracuda Reputation Block List (BRBL)<\/h3>\n
\n
UCEPROTECT<\/h3>\n
\n
PSBL (Passive Spam Block List)<\/h3>\n
\n
SURBL and URIBL<\/h3>\n
How to Get Removed from a DNS Blacklist<\/h2>\n
Confirm the listing and identify which list<\/h3>\n
Find and fix the root cause<\/h3>\n
Verify your authentication records<\/h3>\n
Submit the delisting request through the list’s own process<\/h3>\n
Wait for propagation<\/h3>\n
Monitor continuously afterward<\/h3>\n
Built for Deliverability, Not Just Uptime<\/h2>\n
Immediate DNSBL Alerts<\/h3>\n
Root Cause Detail<\/h3>\n
Delisting Support<\/h3>\n
Continuous Re-Checks<\/h3>\n
Alert Routing by Team<\/h3>\n
REST API + 25+ integrations<\/a><\/h3>\n
![\"Dotcom-Monitor](\"https:\/\/www.dotcom-monitor.com\/wp-content\/uploads\/alert-config-1.webp\")
\nAlerting<\/p>\nSend Deliverability Incidents to the People Who Own Mail<\/h2>\n
\n
Where a Silent Listing Does the Most Damage<\/h2>\n
\n
Receipts, resets, and confirmations<\/h3>\n
\n
Sender reputation for campaigns<\/h3>\n
\n
Shared hosting and cloud IP ranges<\/h3>\n
DNS blacklist monitoring, included with Internet Infrastructure<\/h2>\n
Internet Infrastructure Plan<\/h2>\n
\n
\n$39.95
\nper month
\n
\nStart Free Trial
\n<\/a>
\nCustomer stories<\/p>\nWhat Teams Say After They Switch<\/h2>\n
\nThe real-time alerts and detailed performance analytics have been a game-changer for our website’s uptime. The global monitoring feature ensures our site is optimized everywhere, and the intuitive dashboard makes it easy to track performance. Their customer support is exceptional \u2014 always responsive and efficient.Tomer C.Managing Director \u00b7 Facilities ServicesVerified Capterra review \u00b7 March 2025
\nI use Dotcom tools inside the ISP I work \u2014 it’s a really good and reliable tool for monitoring things along the network and testing network components. I usually use it to diagnose server latency and DNS resolve time.Leonardo J.Network Infrastructure Analyst \u00b7 ISPVerified Capterra review \u00b7 October 2022<\/p>\n
\nCapterra Score reviews<\/p>\n
\nCapterra Score reviews<\/p>\nDNS Blacklist Monitoring \u2014 Common Questions<\/h2>\n
What is a DNS blacklist?<\/a><\/h3>\n
How does DNS blacklist monitoring work?<\/a><\/h3>\n
Why is DNS blacklist monitoring crucial?<\/a><\/h3>\n
How does Dotcom-Monitor aid in DNSBL management?<\/a><\/h3>\n
How long does it take to get removed from a DNS blacklist?<\/a><\/h3>\n
Why is my IP address on a blacklist when I don’t send spam?<\/a><\/h3>\n
How often should you check if your IP or domain is blacklisted?<\/a><\/h3>\n
What’s the difference between an IP blacklist and a domain blacklist?<\/a><\/h3>\n
Find Out You’re Listed Before Your Customers Do<\/h2>\n
\nStart 30-Day Free Trial
\n<\/a>
\n
\nSchedule a Demo
\n<\/a><\/p>\n\n