Blacklist check
Check if an IP address is listed on any email blacklists (DNSBLs). Tests against 45+ known blacklists.
How to read the results
Blocklists are the lists receiving mail servers consult before accepting a message. Being on one does not mean you sent spam. It means something about the address looked like spam to whoever runs that list.
- Not all listings carry the same weight. A few of the major lists are consulted by a large share of mail servers, while many smaller ones are barely used. One listing on a minor list with clean results elsewhere rarely explains a delivery problem.
- The reason and response fields are the useful part. They usually encode a category, such as a dynamic address range, a policy listing, or observed spam. The category tells you whether this is something you did or something about the address itself.
- A timeout is not a pass. It means the list did not answer in time, so the result is unknown rather than clean. Re-run before concluding anything.
- Clean everywhere and mail still failing means the problem is authentication or content, not reputation. Check SPF, DKIM and DMARC alignment next.
What to do about a listing
- Find the cause before requesting removal. Delisting an address that is still sending the offending traffic gets it relisted within days, and repeated delistings are treated less generously each time.
- Check whether the address is even yours to fix. On shared hosting the address is shared, so a neighbour can get it listed. That is your provider's problem to resolve, and it is a reasonable thing to escalate.
- Look for a compromised account or form. The usual cause on a web server is a contact form being abused as a relay, or a stolen mailbox password being used to send bulk mail.
- Then use the list's own removal process. Every reputable list publishes one and most are automatic once the underlying issue stops. Never pay a third party offering to delist you, as they simply submit the same free form.
- Policy listings are not removable in the usual sense. A residential or dynamic range is listed by design, because mail is not expected to originate there. The fix is to send through a proper relay rather than to contest the listing.
Common questions
Why is my IP address on a blacklist?
The common causes are a compromised mailbox sending bulk mail, a contact form being abused as an open relay, a shared address where another customer caused the problem, or a policy listing because the address is in a range not expected to send mail at all. The listing reason usually indicates which.
How long does it take to get removed?
Many lists expire a listing automatically within a few days once the traffic stops. Manual removal requests are often processed within a day. What resets the clock is being relisted, so confirming the cause is fixed before requesting removal matters more than requesting it quickly.
Does one listing mean my email will bounce?
Not necessarily. Servers vary in which lists they consult and how they weigh them, so a listing on a minor list may have no visible effect while one on a widely used list can stop delivery outright. Look at which list flagged you rather than at the count of listings.
Should I pay a service to delist my IP?
No. Removal is free from every reputable list, and these services just submit the same public form you can. Worse, they cannot fix the underlying cause, so the address is relisted shortly afterwards and you have paid for nothing.