How the blacklist check works
Enter an IPv4 address or a domain, and we ask every active blacklist we monitor about it, live.
IP blacklist check
An IPv4 address is checked against 64 IP blacklists, the lists mail servers query before they accept your email.
Domain blacklist check
A domain is checked against 23 domain blacklists, which flag domains seen in spam and phishing links.
A report you can share
Every check is saved as a public report, so you can send the result to your host, your team or a blacklist’s support.
How to read the results
- Listed
- The blacklist has your IP or domain on it. Mail servers that use this list may reject your email or send it to spam. A Delist link takes you to that list’s removal page.
- Not listed
- The list answered, and you’re not on it.
- Not answering
- The list didn’t answer in time. That says nothing about your IP or domain, so check again later.
Listed? How to get delisted
- Find the cause. Common ones: a hacked account or website sending spam, malware on a server, an open mail relay, or a sudden jump in how much you send.
- Fix it first. Most blacklists list you again if the problem is still there, and some make the next removal harder.
- Ask to be removed. Use the Delist link next to each list. Some lists remove you on request, others drop the listing on their own once the spam stops.
- Watch it clear. Add the IP or domain to Blacklist Monitor, and get an alert when it’s delisted, or listed again.
Why IPs and domains get blacklisted
Blacklists add an IP when it sends to their spam traps, when people report its mail as spam, or when it behaves like an infected machine. Some lists also include whole ranges of home and dynamic IPs that shouldn’t send mail directly. On shared hosting, another customer on the same IP can get it listed. Domains get listed when they show up in the links of spam or phishing mail.
Get an alert the next time it’s listed
Blacklist Monitor checks your IPs, domains and whole IP ranges on a schedule and alerts you when anything changes. 32 monitors, free forever.
Questions
Is the blacklist check free?
Yes, with no sign-up. If you run a lot of checks from one IP in a day, we’ll ask you to confirm you’re not a robot.
Can I check an IPv6 address?
Not yet. The check takes an IPv4 address or a domain.
Does it check Microsoft SNDS?
No. SNDS data needs your Microsoft account, so it can’t be part of a public check. Blacklist Monitor can watch SNDS for your IPs once you connect your account.
Which blacklists do you check?
Every active blacklist we monitor. See the full list, with which ones are answering right now and a delisting link for each.
Does every listing hurt my email delivery?
Not equally. Big lists are used by many mail providers, small ones by few. Fix the cause either way, because one listing often leads to more.
How do I get alerted when my IP is listed?
Add it to Blacklist Monitor. Free accounts get 32 monitors checked every 24 hours, and paid plans check more often, down to every 2 hours.