Generator Labs continuously checks your IPs and domains against the data sources listed on this page. Most are public DNS-based blacklists; some are commercial threat intelligence feeds or reputation systems that require special access. The full list is updated as sources are added, deprecated, or merged.

For context on how these sources fit together, see the Complete Guide to Email Blacklist Monitoring. For a dedicated page on any major brand below, follow the "Learn more" links on the featured cards.

Coverage by Category

Counts reflect the currently active data sources, deduplicated by host.

IPv4 Blacklists (RBLs)

Real-time blacklists that list IPv4 addresses associated with spam, open proxies, compromised hosts, or known bad behavior. The foundation of email reputation.

URI Blacklists (URIBLs)

Blacklists that flag domains appearing in spam message bodies rather than sending IPs. Useful for catching campaigns that rotate sending infrastructure.

IPv6 Blacklists

Blacklists covering IPv6 address space. Important as IPv6 adoption grows and spammers pivot to IPv6 sending.

DNS Security Filters

Public and commercial DNS resolvers that block known malicious domains. Being listed here affects access for users of those resolvers.

Microsoft SNDS

Microsoft's internal reputation system for Outlook, Hotmail, and Live.com. Tracks sender IP reputation across Microsoft's consumer mail infrastructure.

Threat Intelligence

Curated threat intelligence feeds covering IPv4, IPv6, domains, and URLs. Aggregated indicators from industry participants and security vendors.

PhishTank

Community-verified phishing database tracking IPs, domains, and URLs hosting phishing content. Widely consumed by browsers, mail filters, and DNS security services.

Project Honey Pot

Distributed tracking service for fraud, abuse, and phishing activity, correlated across thousands of honeypot addresses.

Featured Data Sources

The most widely-consulted reputation systems, with some context on each.

Spamhaus

The most widely consulted set of blacklists in email filtering. Spamhaus zones (SBL, XBL, PBL, DBL, ZEN) are used by a majority of mail servers worldwide. A Spamhaus listing has immediate, global impact on deliverability.

Official site

Barracuda

Barracuda Reputation Block List is used by Barracuda Networks security products and consulted widely outside that ecosystem. Listings often correlate with complaint rates on Barracuda-filtered networks.

Official site

SORBS

Long-running collection of specialized blacklists covering open proxies, dynamic IP ranges, and compromised hosts. Multiple sub-zones target specific abuse categories. SORBS was operated by Proofpoint and wound down in 2024; the zones are no longer updated but historical data is still referenced in some filters.

SpamCop

Generated automatically from spam reports submitted by SpamCop users. Fast listings when complaint volume spikes against an IP; fast delisting when complaint volume drops.

Official site

UCEProtect

Tiered escalating blacklist (Level 1/2/3) covering individual IPs, /24 netblocks, and entire ISPs. Aggressive, widely consulted, and particularly punishing for shared-hosting senders.

Official site

SenderScore

Validity SenderScore rates sending IPs on a 0-100 reputation scale based on spam traps, complaint rates, and filtering results from a large receiver network. Used broadly in receiver filtering policy.

Official site

Abusix

Commercial threat intelligence with multiple specialized zones for authentication, exploit, dynamic, and greylist categories. Used in both direct filtering and derived reputation systems.

Official site

Mailspike

Reputation system that combines real-time blacklist data with sending-history signals. Useful for catching sudden behavior changes on previously clean IPs.

Official site

Invaluement

Commercial blacklist with multiple specialized zones (sip24, ivmURI, etc.) focused on high-precision detection of snowshoe spam and low-volume campaign IPs.

Official site

SURBL

Widely used URI blacklist aggregating domain and URL indicators from multiple sources. Effective against spam that reuses landing-page domains across campaigns.

Official site

Microsoft SNDS

Microsoft's reputation system for Outlook, Hotmail, and Live.com. Rates sending IPs as green, yellow, or red based on complaint rates, spam trap hits, and filter results. A red rating effectively blocks Microsoft consumer mail delivery.

Official site | Learn about Microsoft SNDS monitoring

PhishTank

Community-driven phishing feed consumed by browsers, DNS filters, and email systems worldwide. Verified listings propagate globally within hours.

Official site | Learn about PhishTank monitoring

Project Honey Pot

Distributed tracking system for email harvesters, comment spammers, and phishing operations, correlated across thousands of participating honeypot addresses.

Official site

Full Source Inventory

Every active source grouped by category. Expand a category to see the full list of hosts and zones.

IPv4 Blacklists (RBLs)
URI Blacklists (URIBLs)
IPv6 Blacklists
DNS Security Filters
Microsoft SNDS
Threat Intelligence
  • Facebook Threat Exchange: Domains PREMIUM
  • Facebook Threat Exchange: IPv4 PREMIUM
  • Facebook Threat Exchange: IPv6 PREMIUM
PhishTank
Project Honey Pot

Monitor All of Them, Continuously

Every one of the 136 data sources above, checked automatically for your IPs and domains. Free plan available for 1 host.