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.
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.
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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