Email Blacklist
A database of domains or IPs identified as spam sources, used by email providers to filter incoming mail.
What is Email Blacklist?
Email blacklists (also called DNSBLs or RBLs) are databases maintained by security organizations that track domains and IP addresses associated with spam. When you send an email, receiving servers may check these blacklists and reject or filter your message if you're listed.
Major blacklists include:
- Spamhaus: Most impactful, used by many providers
- Barracuda: Common in enterprise environments
- SORBS: Focuses on IP-based listings
- SpamCop: User-reported spam sources
Getting blacklisted can happen due to:
- High bounce rates (bad email lists)
- Spam complaints from recipients
- Sending patterns that look like spam
- Being on a shared IP with a bad actor
Some blacklists are more serious than others. Spamhaus listing is critical; smaller blacklists may have minimal impact.
Why It Matters
- 1Can instantly kill email deliverability
- 2Some blacklists (Spamhaus) are used by most major providers
- 3Recovery can take weeks and isn't guaranteed
- 4Indicates serious sending problems that need addressing
How to Measure
Use our Blacklist Checker to scan your domain and IP against all major blacklists.
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