URIBL

What it detects

Domains observed in spam messages, with weighting for confidence. URIBL maintains separate sub-lists for high-confidence spam, probable spam, and a 'red list' for active spam sources.

Listing categories

127.0.0.2 (blacklisted — high-confidence spam), 127.0.0.4 (greylist — probable spam, lower confidence), 127.0.0.8 (red list — confirmed active spam source). The red-list flag is the most punitive at receivers.

How to check a listing yourself

Query `<domain>.multi.uribl.com` and inspect the A record. A 127.0.0.x value indicates a listing.

How to get delisted

Submit a delist request through URIBL's removal form. They require evidence the domain is no longer used in spam — typically a 24-hour observation window after cleanup. Greylist entries often clear automatically; red-list entries require manual review.

Other blacklists DomainCare monitors

• SURBL — Domain reputation list focused on URLs found in unsolicited mail. SURBL is one of the most widely deployed domain blocklists at receivers.
• SpamCop SCBL — SpamCop Blocking List — IP blacklist driven by reports submitted by mail recipients.
• DroneBL — IP blacklist focused on compromised hosts — drones, open proxies, brute-force attackers — rather than spam senders.
• Blocklist.de — Community-driven IP blacklist aggregating fail2ban-style attack reports from operators worldwide.