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Spam Blacklist Checker

Check if an IP address is listed on known spam and email blacklist databases (DNSBLs). Diagnose email deliverability issues.

Spam Blacklist Checker (DNSBL)

Check if an IP address appears on major spam blacklists. This tool uses DNS-based lookups (the same method mail servers use) to check your IP against multiple blacklist databases. If your IP is listed, your emails may be rejected or sent to spam folders.
Blacklist Check
IP Address
  

Blacklist Check for 216.73.216.23 (Reverse: 23.216.73.216)
Spamhaus ZEN (SBL+XBL+PBL) (zen.spamhaus.org)✔ Clean
SpamCop (bl.spamcop.net)✔ Clean
Barracuda Reputation (b.barracudacentral.org)✔ Clean
SORBS (dnsbl.sorbs.net)✔ Clean
SORBS Spam (spam.dnsbl.sorbs.net)✔ Clean
Mailspike (bl.mailspike.net)✔ Clean
UCEPROTECT Level 1 (dnsbl-1.uceprotect.net)✔ Clean
PSBL (psbl.surriel.com)✔ Clean
SpamRATS Dynamic (dyna.spamrats.com)✔ Clean
SpamRATS NoPtr (noptr.spamrats.com)✔ Clean
S5H All (all.s5h.net)✖ LISTED (127.0.0.2)
InterServer RBL (rbl.interserver.net)✔ Clean
✖ 216.73.216.23 is listed on 1 of 12 blacklists. This may affect email deliverability. Visit each blacklist's website to request delisting.

 

 

About This Tool

Email blacklists (also known as DNSBLs or RBLs) are databases of IP addresses and domains known to send spam. If your server IP or domain ends up on a blacklist, your emails may be rejected or sent to spam folders by recipient mail servers. This tool checks your domain or IP against known blacklist databases to help diagnose email deliverability problems. If you are finding that your emails are not reaching recipients, a blacklist listing is one of the most common causes.

How to Use

Enter a domain name or IP address and click the check button. The tool queries multiple spam blacklist databases and reports whether your domain or IP appears on any of them.

Tips & Best Practices

If you find your IP on a blacklist, the most common causes are compromised email accounts sending spam, an open relay on your mail server, or shared hosting where another user on the same IP was sending spam. Most blacklists have a delisting process. Visit the blacklist website for removal instructions. To prevent future listings, use strong email authentication (SPF, DKIM, DMARC) and monitor your server for unauthorized email sending.

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