Email blacklist checker
Use this email blacklist checker to test your mail servers or one IPv4 address against DNS blocklists whose terms allow it. See which lists were skipped and how to get removed.
Free, no account. Ten checks per hour, shared by our DKIM, blacklist, MTA-STS and BIMI checkers.
Email deliverability checks
Check the sending identity, domain policy, receiving servers and an actual received message together. These checks explain configuration; they cannot certify delivery to an inbox.
- SPF
- Authorize your sending IP and trace the DNS lookup budget.
- DMARC / DKIM
- Check policy, alignment settings, reporting permissions and public keys.
- MX
- Inspect incoming servers, addresses, reverse DNS and the public blocklist.
- Email headers
- Read actual receiver results, forwarding assertions and hop delays locally.
- DKIM
- Read the public key for a selector, or try common provider selectors.
- Blocklists
- Check mail server addresses on DNS blocklists, with removal steps.
- MTA-STS
- Check the TLS policy for incoming mail, its MX match and TLS reports.
- BIMI
- Check the BIMI record, the SVG logo, the certificate and DMARC readiness.
Google and Yahoo bulk sender requirements
Requirements checked 2026-10-12. Google applies its bulk rules above 5000 messages per day to personal Gmail accounts. Yahoo describes bulk senders without publishing the same numeric threshold.
- Publish SPF and sign with DKIM. Publish DMARC with at least p=none, and align the visible From domain with a passing SPF or DKIM identity.
- Use valid forward and reverse DNS and correctly formatted messages. Google also requires TLS transport. Keep reported spam rates below 0.3 percent.
- Marketing and subscribed messages need one-click unsubscribe headers plus a visible unsubscribe link. Honor unsubscribe requests within two days.
- Google requires RSA DKIM keys of at least 1024 bits and recommends 2048 bits. A DNS key check does not prove that outgoing mail is signed.
Spam rate, unsubscribe behavior and real SMTP TLS are outside a DNS check. Verify them with your mail service and a received message.
Google sender guidelinesYahoo sender requirementsYahoo bulk sender definition
An email blacklist checker asks DNS blocklists whether an address is listed. Enter a domain to check its mail servers and website address, or one IPv4 address. We query five lists whose terms allow it: SpamCop, PSBL, DroneBL, 0spam and UCEPROTECT Level 1. Each listing comes with removal steps, and each skipped list with the reason.
How to use this checker
- Enter a domain or address
- For a domain, we check the IPv4 addresses of its MX servers and of the domain itself, up to six. To check one server, enter its public IPv4 address.
- Read each list
- Before trusting a list, we ask it for its RFC 5782 test entries. A list that fails them is marked could not verify for every address.
- Get removed
- Fix the cause first, such as a hacked mailbox or a web form that sends spam. Then follow the removal steps shown for each list that names your address.
Questions about this checker
Check your business in AI answers
Email records protect your name in the inbox. The free AI visibility scan shows how ChatGPT and other assistants describe your business.