How to check if your domain is blacklisted

Domain lists versus IP lists

There are two kinds of listing to understand. IP blocklists concern the server that sends your mail. Domain blocklists concern domain names, such as the one in your From address or in links in your message body.

If you send through Google Workspace, Microsoft 365 or a sending platform, the sending IPs belong to the provider and are shared with other customers. A listing on one of those IPs is mostly the provider's job to deal with. A listing on your own domain is yours to resolve.

The most common lists

• Spamhaus has several lists. The SBL covers sources of spam, the XBL covers exploited machines, the PBL lists address space that should not be sending mail directly, and the DBL lists domains. A listing on the DBL is a domain problem.
• SURBL and URIBL are domain lists often used to check links in message bodies.
• Others, such as Barracuda and SpamCop, are used by particular receivers.

Each list has its own listing criteria and its own removal process, and you should read the operator's own documentation rather than relying on a third party's summary.

How to check

1. Run your domain through our free blacklist check, which looks the domain up against several widely used lists.
2. If you send from your own IP, also look up that IP on each major list operator's own lookup page.
3. Check the links in your messages too. A tracking or shortener domain can be listed even if your own domain is clean.

One caveat: some lists, notably Spamhaus, restrict or return errors for queries that come through large public DNS resolvers. If a result says it could not be checked, that is not the same as clean. Our checker reports those as unavailable and marks the result as partially checked, instead of pretending it is clear.

What to do if you are listed

1. Do not panic, and do not keep sending at the same volume. Pause or reduce the affected sending.
2. Find out why. Common causes are a compromised mailbox or website, sending to old or purchased lists, spam traps, and high complaint rates.
3. Fix the cause first. Delisting requests made while the problem continues usually get relisted.
4. Follow the list operator's own removal process. Most have a lookup page that explains the reason for the listing and how to request removal.
5. After removal, resume gradually, and monitor for a repeat.

Be skeptical of delisting services

Blocklist operators generally offer free or documented removal for legitimate senders. Be wary of any site that charges to remove you from a list it does not run, or that promises instant removal from all lists. A listing is a symptom of something your sending did.

Reduce the chance of being listed

• Use a clean, verified list and remove bounces quickly.
• Honor opt-outs promptly.
• Keep volume steady and ramp slowly. See the warm-up guide.
• Keep your spam complaint rate low. See the complaint rate guide.
• Secure your mailboxes and website, so no one else sends as you.

Catch it earlier

The worst way to find out about a listing is a drop in replies a week later. OutboxWatch's paid monitoring is designed to check your domains daily and alert you when a new listing appears, and the free checker is good for a quick look at any time.