Email Blacklist Check DNSBL and RBL Lookup
Check whether your mail server's IP address is on a spam blacklist. This free DNSBL test looks up your IP addresses on eight major blacklists and shows, list by list, whether you are listed and why.
At a glance
- 8 blacklists: Spamhaus ZEN, SpamCop, Barracuda, PSBL, SpamRATS, UCEPROTECT Level 1, Mailspike and DroneBL.
- IP or host name: enter an IPv4 address or a host name; up to 5 IPv4 addresses of the host are checked.
- Per-list result: listed, not listed, refused or no answer, with the return code and the listing reason (TXT record).
- Non-intrusive: only DNS lookups are made; your server is never contacted.
- Multiple locations: run the lookup from up to 3 locations at once without an account.
- Free: no sign-up; export results as PDF, CSV or JSON.
How to check if your IP is blacklisted
- Enter your mail server's IPv4 address or host name, for example
mail.example.com. - Select one or more locations.
- Click Run Test. Each location queries all eight blacklists in parallel.
If any blacklist lists one of your addresses, the result is marked as an error and the table shows which list, the return code and the reason the list gives.
Which blacklists are checked
| Blacklist | Zone |
|---|---|
| Spamhaus ZEN | zen.spamhaus.org |
| SpamCop | bl.spamcop.net |
| Barracuda Reputation Block List | b.barracudacentral.org |
| Passive Spam Block List (PSBL) | psbl.surriel.com |
| SpamRATS | all.spamrats.com |
| UCEPROTECT Level 1 | dnsbl-1.uceprotect.net |
| Mailspike | bl.mailspike.net |
| DroneBL | dnsbl.dronebl.org |
What is a DNSBL?
A DNSBL (DNS-based blackhole list), also called an RBL (real-time blackhole list), is a list of IP addresses known to send spam or to be compromised. Receiving mail servers look up the sender's IP in these lists through DNS: the IP is reversed and queried under the list's zone, for example 4.3.2.1.zen.spamhaus.org for 1.2.3.4. An answer in the 127.0.0.x range means the IP is listed. Mail from listed IPs is often rejected or sent to spam.
Why some lists show "refused"
Some blacklists, notably Spamhaus, refuse queries that arrive through large public DNS resolvers. A "refused" result means the list declined to answer, not that your IP is listed. Check that list's own lookup page to confirm.
How to get removed from an email blacklist
- Fix the cause first: find and stop the spam source, such as a compromised account, an infected computer, an open relay or a form that sends mail without limits.
- Check your mail setup: make sure reverse DNS (PTR), SPF, DKIM and DMARC are configured for the sending IP and domain.
- Request delisting: follow the removal process on each list that lists you. Some lists expire entries automatically once spam stops.
- Re-test: run the blacklist check again to confirm the listing is gone.
Related free tools
- Email Server Test: check that your SMTP, IMAP or POP3 server accepts connections and logins.
- DNS Trace Test: check your MX, PTR, SPF and DMARC records.
To watch your mail server IPs on blacklists continuously with alerts, see Dotcom-Monitor.
Frequently asked questions
How do I check if my email server is blacklisted?
Enter your mail server's IP address or host name in this email blacklist check and run it. The result shows, for each of eight major DNSBLs, whether the IP is listed, the list's return code and the listing reason.
What is the difference between a DNSBL and an RBL?
None in practice. Both names describe lists of IP addresses published through DNS so mail servers can block spam sources. RBL (real-time blackhole list) was the name of the first such list; DNSBL is the general term.
Can I check a domain instead of an IP address?
You can enter a host name, and the test checks its IPv4 addresses. It does not check domain-based blacklists (URI or domain block lists), only IP-based DNSBLs.
Why is my IP listed on a blacklist?
Usually because spam or malware traffic came from it: a compromised mailbox or website, an infected device, an open relay, or a shared IP used by another sender. Some lists also list whole ranges with a bad reputation.
How long does it take to be removed from a blacklist?
It depends on the list. Some remove an IP within hours of a delisting request, others expire listings automatically after a period without spam, typically from 24 hours to a few weeks.
What does "refused" mean for Spamhaus?
Spamhaus does not answer queries that come through large public DNS resolvers, and returns a special 127.255.255.x code instead. It means the lookup was refused, not that your IP is listed.
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