# Domain Blocklist Monitoring (Spamhaus, SURBL, URIBL) URL: https://warmerly.com/features/blocklist-monitoring > Warmerly checks every sending domain against Spamhaus DBL, SURBL and URIBL daily from a dedicated resolver, and tells a real listing from a refused query. Blocklist monitoring # Know you are listed before your reply rate tells you A domain blocklisting can take a sending domain from healthy to unusable overnight. Warmerly checks yours daily against Spamhaus DBL, SURBL and URIBL — from its own resolver, because these zones refuse queries that arrive via public DNS. [Start free](https://app.warmerly.com/register?cta=feature_page_start_free)[Continue with Google](https://app.warmerly.com/register?cta=feature_page_google&provider=google)[See pricing](https://warmerly.com/pricing) Blocklist monitoring outbound.example.com Checked daily from our own resolver, because these zones refuse queries that arrive via public DNS. A refusal is reported as an error, never as a listing. 1 listing Spamhaus DBLdbl.spamhaus.orgClear SURBLmulti.surbl.orgListed — spam / abuse URIBLmulti.uribl.comClear 3 Domain blocklist zones queried daily 0 False listings from a refused query — refusals are errors, not hits Own Dedicated resolver, because public DNS gets refused The zones that matter for domains ## Spamhaus DBL, SURBL and URIBL These three are the domain-reputation lists that filtering systems actually consult when deciding what to do with a message that mentions your domain. Warmerly queries each one by plain DNS lookup for every sending domain in your workspace, records the verdict, and links straight to the right delisting form when something appears. The trap most checkers fall into ## A refused query is not a listing Every one of these zones signals 'your query was refused' using an address inside the same 127.x range it uses for real listings. Spamhaus answers 127.255.255.x; SURBL and URIBL answer 127.0.0.1. Any checker that treats a 127.x answer as a hit will report every customer as blacklisted the moment it gets rate-limited. Warmerly classifies each zone's codes explicitly and treats anything it does not recognise as an error — never as a listing. - ✦Refusal codes are checked before listing codes, because they are numerically adjacent - ✦SURBL and URIBL bitmasks are decoded properly, not pattern-matched - ✦An unrecognised code produces 'status unknown', which is what the UI then says Its own resolver ## Public DNS gets you refused, not answered Spamhaus, SURBL and URIBL all refuse queries arriving from Cloudflare, Google and Quad9 resolvers. A monitoring feature built on the default system resolver therefore returns refusals for every domain it checks, forever, and either reports nothing or reports nonsense. Warmerly runs its checks through a dedicated resolver so the answers are real. A domain blocklisting is one of the few deliverability problems that is genuinely binary. One day your mail lands; the next day a large share of receivers reject or junk it outright because your domain appears on a list they consult. The listing rarely announces itself. What you notice, usually a week later, is that the replies stopped. ## Domain lists and IP lists are different problems IP blocklists such as Spamhaus SBL list sending addresses. If you send through Google Workspace, Microsoft 365 or any shared provider, the IP is not yours and a listing there is not yours to fix — the provider handles it, and it is largely out of your control. Domain blocklists list the domains that appear in the message: the sending domain, the domains of links in the body, and the domains a reply would go to. Those are yours. Spamhaus DBL, SURBL and URIBL are the three that matter, and a listing on any of them follows your domain across every provider you send through. Changing ESP does not help. That is why Warmerly monitors domain reputation rather than reporting an IP you do not own. ## How domains end up listed - ✦Sending to spam traps — recycled addresses that once belonged to real people and now exist only to catch senders working from stale lists - ✦A sharp volume increase from a domain with no sending history, which is the standard signature of a compromised or throwaway domain - ✦High complaint rates, where recipients hit 'report spam' rather than unsubscribing - ✦Linking to a domain that is itself listed — URIBL and SURBL list what a message points at, not only who sent it - ✦A shared or previously abused domain, which is the risk of buying an aged domain with an unknown history The first cause is by far the most common among cold senders, and it is entirely preventable. Spam traps are why verification before import is not optional, and why Warmerly ships verification in the same product rather than selling it separately. Verify before you import, not after you are listed Spam-trap hits are the leading route onto a domain blocklist for cold senders, and a trap address is indistinguishable from a real one by eye. Running a list through verification first costs minutes; delisting costs weeks. ## What we do with a listing The domain's mailboxes show the listing on their own pages with the zone name, what that zone's code actually means — spam domain, phishing, malware, abused legitimate domain — and a direct link to the delisting form for that specific list. The health score reflects it, which means the affected mailboxes' sending allowance narrows rather than continuing at full volume into receivers that are already rejecting them. Warmerly does not attempt to submit delisting requests on your behalf. Every one of these lists requires the domain owner to attest to what was fixed, and an automated submission from a third party is both against their terms and a good way to get a request denied and a domain re-listed faster. ## Getting delisted - Find the cause before you request removal. A delisting granted while the behaviour continues is followed by a faster re-listing and a worse standing. - Stop sending from the domain. Continuing to send into rejections during a listing deepens the problem. - Clean the list. Run the full recipient set through verification and remove everything that is not confidently deliverable. - Fix authentication if it is part of the picture — a listed domain with no DMARC enforcement is a much harder case to argue. - Submit the delisting request through the zone's own form, describing what changed. Spamhaus DBL removals are often quick when the cause is clearly addressed; SURBL and URIBL vary. - Resume slowly. Treat the domain as new again and let the ramp rebuild volume rather than returning to previous levels immediately. Prevention, in order of effect - →[Verify addresses before they reach a campaign](https://warmerly.com/features/email-verification) - →[Suppression — never mail an unsubscribe or a hard bounce twice](https://warmerly.com/features/suppression-list) - →[Warmup — ramp instead of spiking](https://warmerly.com/features/email-warmup) ## Why 'status unknown' is a feature When a check cannot get a reliable answer — a refused query, a timeout, an unrecognised response code — Warmerly says the status is unknown and will try again on the next run. It does not round that to 'clear', because a monitor that reports clear when it did not actually check is worse than no monitor at all: it converts an unknown into a false assurance. It also does not round it to 'listed'. Telling a customer their domain is blacklisted when in truth the resolver was rate-limited is the failure mode that makes people distrust the whole product, and it is the single most common bug in home-grown blocklist checks. ## Questions ### Which blocklists does Warmerly check? The three domain-reputation zones that matter for sending domains: Spamhaus DBL, SURBL and URIBL. These list domains rather than IP addresses, which is the reputation you own and can fix. ### Why not check IP blocklists too? If you send through Google Workspace, Microsoft 365 or any shared host, the sending IP is not yours and a listing on it is not yours to resolve. Reporting it would produce alarm you cannot act on. ### How quickly will I know if my domain gets listed? Checks run daily per sending domain, and the result appears on the affected mailboxes with the zone, the meaning of the code, and a delisting link. ### Can Warmerly get my domain delisted? No, and no reputable tool can. Every list requires the domain owner to submit the request and attest to what was fixed. Warmerly identifies the listing, explains what the code means, and links you straight to the right form. ### My domain shows 'status unknown' — is that bad? No. It means the last check could not get a reliable answer, usually a refused or rate-limited query, and it will be retried. It is deliberately not reported as clear, because an unchecked domain is not a clean domain. Keep reading [Deliverability monitoring→](https://warmerly.com/features/deliverability-monitor)[Email verification→](https://warmerly.com/features/email-verification)[Email warmup→](https://warmerly.com/features/email-warmup)[Free deliverability checker→](https://warmerly.com/deliverability-checker)[Free email blacklist checker→](https://warmerly.com/blacklist-checker) Summarize with AI [ChatGPT](https://chatgpt.com/?q=In%20a%20succinct%20way%20(few%20short%20paragraphs%20and%2For%20bullets)%2C%20tell%20me%20what%20it%27s%20about%20and%20key%20highlights.%0A%0Ahttps%3A%2F%2Fwarmerly.com%2Ffeatures%2Fblocklist-monitoring)[Claude](https://claude.ai/new?q=In%20a%20succinct%20way%20(few%20short%20paragraphs%20and%2For%20bullets)%2C%20tell%20me%20what%20it%27s%20about%20and%20key%20highlights.%0A%0Ahttps%3A%2F%2Fwarmerly.com%2Ffeatures%2Fblocklist-monitoring)[Perplexity](https://www.perplexity.ai/search?q=In%20a%20succinct%20way%20(few%20short%20paragraphs%20and%2For%20bullets)%2C%20tell%20me%20what%20it%27s%20about%20and%20key%20highlights.%0A%0Ahttps%3A%2F%2Fwarmerly.com%2Ffeatures%2Fblocklist-monitoring) [Plain-text version for LLMs](https://warmerly.com/features/blocklist-monitoring/llms.txt)[llms.txt](https://warmerly.com/llms.txt) ## Check your sending domain Run a free check on any domain — authentication and reputation — and see what receivers see before your next campaign goes out. [Start free](https://app.warmerly.com/register?cta=feature_page_footer_start_free) --- Source: https://warmerly.com/features/blocklist-monitoring Site index: https://warmerly.com/llms.txt Full content: https://warmerly.com/llms-full.txt