Check blocklists
Check MX and explicitly discovered SPF sender IP addresses using an approved reputation provider.
Enter only the domain, such as example.com – without https://, a path or an email address.
A new check is available every 5 minutes per tool and domain. Until then, you see the saved result.
What the tool accesses
Public DNS and IP-pinned HTTPS to the configured provider. Only public mail IP addresses discovered through MX and SPF are checked. Opening this page does not start a check.
What exactly is checked?
- Find MX targets and their public IPv4/IPv6 addresses from DNS evidence.
- Identify explicit SPF sender IP addresses and safely resolved SPF endpoints separately.
- Evaluate no more than ten approved lists per IP address through the configured provider.
- Show blocklist hits, unsupported IP families, partial failures and policy advisories separately.
How is the result determined?
Passed means only that the named IP addresses were not listed on any successfully queried spam blocklist at the time of the check. A policy advisory is not a spam blocklist hit; partial failures never justify an all-clear.
- Checker
1.0.0- What the tool accesses
- Public DNS and IP-pinned HTTPS to the configured provider
- Technical standards and sources
- Transparent provider sources and their respective terms of use
A technical snapshot, not a certificate or a delivery guarantee. Methodology public-tools-v1. Reviewed on 20.08.2026.