Free email blacklist checker. Is your email server on a spam list?
If your sending address lands on a spam blocklist, your email can bounce or go to junk. Enter the IP address your email is sent from to check six free blocklists in seconds.
What a blacklist is
A blacklist (also called a blocklist) is a public list of internet addresses that have recently sent spam or shown signs of being hacked. Mail servers ask these lists about every incoming email, and may bounce or junk mail from an address that is listed.
Addresses usually land on a list because something sent spam from them: a hacked mailbox, an infected computer, a website form abused by spammers, or a neighbour on the same shared server.
Which address to check
Blocklists list the address of the server that sends the email, not your domain name. If you send from Microsoft 365, Google Workspace or another email service, your mail leaves from their shared servers, and they handle listings on them. This check matters most if you send from your own mail server, a website, a copier or a sales tool.
To find the sending address, paste the headers of an email you sent into the email header analyzer. If your email is going to spam and you use Microsoft 365 or Google, run the email and DNS checker first: missing sender records are the more common cause.
Which lists we check, and which we do not
We check six free public lists: SpamCop, PSBL, Mailspike, UCEPROTECT level 1, DroneBL and 0spam. We do not check Spamhaus, the list most mail providers rely on, because it refuses lookups sent through public DNS services like the one this tool uses, or Barracuda, which asks that the servers that query it register first. Check both on their own free lookup pages.
A result here is a snapshot: lists add and remove addresses all the time, so not being found today is no promise about tomorrow. Treat it as one clue, not a clean bill of health.
Common questions
How do I check if my email is blacklisted?
Enter the IP address your email is sent from above. We ask six free blocklists whether that address is on them and explain the answer in plain English. Then check Spamhaus and Barracuda on their own free lookup pages, because this tool cannot ask them.
Which IP address should I check?
The address of the server that sends your email. If you send from your own mail server, a website, a copier or a sales tool, it is that system’s public address. You can find it in the hidden details (headers) of an email you sent: paste them into our email header analyzer and look for the first server outside your own network.
We use Microsoft 365 or Google Workspace. Should we check?
Usually not. Your email goes out from Microsoft’s or Google’s shared servers, and they handle any listing on those addresses. If your mail from Microsoft 365 or Google is going to spam, the cause is more often missing sender records; run the email and DNS checker on your domain instead.
Does "not found" mean my address is clean?
Why don’t you check Spamhaus?
Spamhaus refuses lookups sent through public DNS services, and this tool runs on one. Rather than guess, we leave it out and link to its own free lookup page.
How do I get my IP address off a blacklist?
Fix the cause first: usually a hacked mailbox, an infected computer, or a website form that sends spam. Then use each list’s own lookup page to see why the address was listed and ask for removal. Some lists remove an address on their own a few days after the spam stops.
Can I check a domain or an IPv6 address?
Not with this tool. It checks IPv4 addresses (four numbers separated by dots), which is what nearly all blocklists cover. Domain blocklists work differently and are not included.
Is anything I enter saved?
No. The address is sent to the blocklists to ask the question, and the answer may be cached for up to 5 minutes so repeat checks are quick. We do not keep a list of the addresses people check.
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