What is URIBL?

URIBL (URI Blocklist) operates similarly to SURBL, scanning email content for links to domains with poor reputation. It's heavily integrated with SpamAssassin and many commercial email gateways, making it a significant factor in spam scoring even if it doesn't directly block messages.

Impact Level: Medium-High. URIBL listings add spam points rather than causing outright rejection, but those points accumulate. A URIBL hit combined with other factors often pushes mail over the spam threshold.

URIBL zones:

• multi.uribl.com - Combined zone covering multiple threat types
• black.uribl.com - Known spam domains
• grey.uribl.com - Suspected spam domains (lower confidence)
• red.uribl.com - Domains from known spam sources

How to check: Use uribl.com/lookup to check your domains.

What triggers listing:

• Domain appears in spam honeypot collections
• Links used in phishing attempts
• Domain nameservers or registrar patterns associated with spam
• Association with other listed domains (shared hosting, same registrant)

Delisting process: Submit a removal request at admin.uribl.com. Processing can take several days. You need to demonstrate legitimate ownership and use of the domain.

URIBL is the customs inspector checking every parcel in your cargo hold - even if your manifest is pristine, contraband links will get your shipment quarantined.