Email blacklist checker
Check whether a domain or IPv4 address appears on the reputation lists used by mail systems.
Try
Check public DNS blocklists
DNS-based blocklists publish IP reputation signals used by receiving mail servers. A listing is a diagnostic clue, not proof that every recipient will reject your mail.
- Resolve a domain to its current IPv4 addresses
- Query each supported DNS blocklist
- Show the exact listed IP addresses
- Keep each provider’s result separate
Resolve
Domain to address
The domain is resolved to the IPv4 addresses sitting behind it.
Query
Ask every list
Each supported blocklist is queried for those addresses.
Listed
A listing is a clue
It means an operator recorded abuse from that address.
Effect
Receivers decide
Some reject on a listing, many only weigh it. Delisting is per operator.
Common questions
- What is a DNS blocklist?
- A published list of IP addresses an operator has seen abuse from. Mail servers query it before accepting a message.
- I am listed. What now?
- Go to that operator’s own site and use its delisting form. Every list is run separately with its own process.
- Why is a shared IP listed?
- On shared hosting one bad sender affects everyone on that address. A dedicated IP avoids it.
- Does one listing block my mail?
- Usually not. Most receivers weigh a listing among other signals, though a few reject on the major lists alone.
- Why check a domain when lists hold IPs?
- The domain is resolved to its addresses first, then each address is checked.
Use these checks during signup
The API returns allow, review, or block with the reasons behind it.