Free Email Blacklist Checker, Check DNSBL Listings | Mailthentic
Mailthentic
Free Tool, No Signup Required

Email Blacklist Checker

Check whether a domain or mail server IP is listed on major email blacklists. A listing can send your mail straight to spam.

What is an email blacklist?

An email blacklist, or DNSBL, is a list of IP addresses known for sending spam. Mailbox providers check these lists before accepting mail. If your sending IP is listed, your messages can be rejected or sent to spam, even to valid recipients.

What to do if you are listed

  • Find and fix the cause, often a compromised account, an open relay, or sending to bad lists.
  • Clean your list so you stop hitting spam traps and invalid addresses.
  • Request delisting through the blacklist operator once the issue is resolved.

Cleaning your list is the best prevention. Verify before you send with the free email checker.

Protect your sender reputation

Verify your list before every send to avoid spam traps and bounces that get you blacklisted.