The Top Email Blacklists and How to Check If You're On One

There are hundreds of email blacklists, but only a handful have significant impact on your deliverability. Here are the ones that matter for cold emailers in 2026.

Spamhaus SBL (Spamhaus Block List)

The most influential blacklist in the world. Being on Spamhaus is a deliverability emergency. It is referenced by most major email providers and can result in near-total inbox blocking. Spamhaus lists IPs and domains based on spam trap hits, abuse reports, and known spam sources.

Spamhaus DBL (Domain Block List)

Similar to SBL but focused specifically on domains rather than IPs. If your sending domain is on the DBL, emails from that domain will be filtered across the board.

Barracuda BRBL

Used by organizations running Barracuda email security appliances. Being listed here affects your ability to reach prospects at companies using Barracuda firewalls.

SpamCop

A complaint-driven blacklist. When recipients report your email as spam through SpamCop, your IP gets listed. Listings are temporary and usually expire within 24-48 hours if complaints stop.

SURBL and URIBL

These blacklists focus on URLs found in email content. If a link in your email points to a domain listed on SURBL or URIBL, your email is filtered. This is another reason to minimize links in cold emails.

How to check all of them at once

Rather than checking each blacklist individually, use the free blacklist checker at Warm Inboxes. It scans your domain and IP against all major blacklists and reports results in one view.

Monitoring cadence

Check blacklists weekly during active campaigns. Check immediately if you notice a sudden drop in open rates or an increase in bounces. Early detection prevents extended damage.

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