How we check, and what a check cannot tell you
Every result on this site is a reading of public information at a moment in time. This page says what each reading covers, what it does not, and how to tell us when we are wrong.
The domain check
What it reads. The DNS records a domain publishes: SPF, the DKIM key at the selectors we try, DMARC, MX, and the reputation of the sending sources the domain authorises.
What it establishes. That a record exists, that it parses, and what policy it declares.
What it cannot establish. That your messages are actually signed, that signatures verify, or that they align with your From domain — verification needs a real message, not a DNS record. No tool can say whether your mail reaches an inbox, including ours. That every sending source is covered. Your SPF record names them, but we do not follow the ones that point at a provider — for most senders that means we check nothing at all, and the result reads unknown.
What it deliberately does not do. It does not predict inbox placement, score a domain out of ten, or turn a configuration reading into a reputation claim.
Sources
Our answers come from primary sources where they exist: the RFCs, the mailbox providers' own published requirements, and M3AAWG's published practice. Where a vendor's documentation is the only source, we say so. Each article lists what it stands on.
Blocklists
We read your authorised sending sources from your SPF record, then check those addresses against a named set of blocklists. We show which lists we checked and which addresses.
Today, that set is: Barracuda, SpamCop, PSBL Surriel.
We do not follow include: mechanisms. Where your SPF record delegates to a provider, such as an email platform or an office suite, we do not expand it, so we check none of that provider's addresses. For most senders that means we check nothing and report unknown. It is not a finding about your domain.
Spamhaus was not checked. Its free service is limited to non-commercial use, and this tool has no commercial licence for it.
When we are wrong
Tell us: hi@cakemail.com — name the page and what is wrong. We check it against the sources and correct it. Corrections are published, not quietly patched.