IP Blacklist (DNSBL) Checker
Check whether your mail server's IP is listed on major spam blacklists that could be blocking your emails.
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How it works
DNSBLs (DNS-based Blackhole Lists) are shared blacklists that mail servers check before accepting an email. If your sending IP ends up on one — often because of a compromised account or a shared hosting neighbor — your emails silently start landing in spam or getting rejected.
This tool checks your IP against the major public blacklists at once, so you can catch a listing early and start the delisting process before it hurts deliverability.
Related reading
Frequently asked questions
I'm on a blacklist — how do I get removed?
First fix the underlying cause (secure a compromised account, stop any outbound spam), then submit a delisting request directly to each blacklist that flagged you — most have a public removal request form, and delisting isn't automatic even after the issue is fixed.
Why is my IP blacklisted when I never sent spam?
On shared hosting or a shared IP pool, another customer's abuse can get the whole IP listed — this is one of the most common causes and is unrelated to anything you personally did.
How often should I check?
Monthly is reasonable for most senders; check immediately if you notice a sudden drop in email delivery or open rates, since a fresh blacklisting is a common cause.
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