What this check does

Enter the public IP that sent the message. You can usually find it in trusted receiving headers or your email provider’s logs. Private network addresses and hostnames are not valid inputs for this check.

How to read your result

The report shows the response from each connected source. Listed, not listed, unavailable, unsupported, and timed-out results remain distinct. A clear result covers only the sources checked at that time and cannot guarantee delivery.

What to do next

For a listing, confirm that the IP is yours or assigned to your provider, investigate the cause, and follow the list operator’s instructions. Shared-IP customers may need their provider to handle the issue.

Common questions

Can I check my laptop or router’s private IP?

No. Use the public IP that actually sent the email.

Does “not listed” guarantee inbox delivery?

No. Mailbox providers also use their own reputation, authentication, content, and recipient-engagement signals.