{"uid":"cap_z5OZhn4ccDUOQLm6NzaJF","slug":"ip-listed-on-sorbs-dul-dnsbl-check-d0d11501","name":"IP Listed on SORBS DUL DNSBL Check","description":"Is this IPv4 address listed on sorbs dul (dul.dnsbl.sorbs.net)? Performs the DNSBL query (reversed octets under dul.dnsbl.sorbs.net, via Cloudflare DoH) and returns listed yes/no with the return codes and, where the list publishes one, the reason text. One list, one precise answer. $0.01 per lookup.","url":"https://ip.intel.rallylive.ca/ip/blacklist/sorbs-dul?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_kag_PQQqpF9-PVozjrjlz","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Checks whether a given IPv4 address is listed on the SORBS DUL (Dial-Up List) DNS blocklist at dul.dnsbl.sorbs.net and returns listed status, return codes, and reason text.","exampleAgentPrompt":"Can you check if the IP address 203.0.113.45 is listed on the SORBS DUL dial-up blocklist and tell me the return code and reason if it is?","exampleUseCases":[{"title":"Email server spam filter validation","prompt":"Before accepting this email, can you check if the sending IP 198.51.100.22 is listed on the SORBS DUL blocklist? I want to know if it's flagged as a dynamic or dial-up address."},{"title":"Outbound mail deliverability check","prompt":"I'm troubleshooting why our emails are being rejected — can you look up whether our server IP 203.0.113.10 appears on the SORBS DUL list and what reason code it returns?"},{"title":"Suspicious connection investigation","prompt":"We got an inbound connection from 185.220.101.5 and I want to know if it's on the SORBS dial-up user list — can you do a DNSBL lookup and give me the result including any reason text?"}],"resultDescription":"Returns whether the IPv4 address is listed on SORBS DUL (yes/no), the DNSBL return codes, and the reason text published by the list if available.","failureModes":["Invalid or non-routable IPv4 address provided — returns error or no result","SORBS DUL service unavailable — DNS query fails via Cloudflare DoH","IPv6 address provided — endpoint only supports IPv4","Network timeout reaching Cloudflare DoH resolver"],"whenToPreferThis":"Use this endpoint when you need a precise, single-list check specifically against the SORBS DUL (dynamic/dial-up) blocklist, rather than a broad multi-list reputation check. Ideal for email security pipelines, spam filtering, and identifying dynamic IP ranges where SORBS DUL is the authoritative reference.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-13T00:41:48.458Z","isFirstParty":false,"canonicalSlug":"ip-listed-on-sorbs-dul-dnsbl-check-d0d11501"}