Paste anything.

A domain, an email address, an IP, or a whole message pasted in. We work out what it is and answer the question that string can actually answer.

Send a real campaign
DNS cannot name the address that actually sent your mail. A message can.
Which blocklists answer
Re-probed hourly. A dead list returns the same silence as a clean result.
Your sending platform
What Klaviyo, Mailchimp, Sendgrid and the rest changed, with dates.
How old is this shelf
Every claim's date, published — including the ones that are getting old.

What you get, and what we refuse to give you

Why not a score? We have watched two different tools score the same campaign at 85 percent and 40 percent inbox placement. Scores are why nobody trusts this category. You get findings, each one traceable to a rule with a date.

What it can and cannot see. DNS shows what you have published: SPF, its lookup count, DMARC and its policy, DKIM keys on the selectors the major platforms use, BIMI and MX. It cannot see your consent records, your subject lines, or whether DKIM aligns on a real message, and it says so rather than guessing. Have a real message? Paste its headers and get the alignment verdict DNS cannot give.

On blocklists, two refusals. We will not expand your sending platform’s ranges. A shared pool’s reputation and its removal channel belong to the platform, so handing you a stranger’s listed address hands you a fire you cannot put out — we name the platform instead. And we will not read a list’s silence as good news: every list here answers an entry it is required to publish before we believe anything it says about you, so a list that declines is reported as declined rather than as clean. Most checkers cannot tell those two apart.

What the box does with each thing

a domain: authentication, then 24 blocklists
an address: the domain it sends from
an IP: every list that answered today, sorted by whether the entry is even about it
a message: all of the above, plus the consent and content rules no other checker reads
a record: we say what it is, and which domain to give us instead

A message is the only one of those that can answer the question people actually arrive with, because it carries the address that really sent your campaign and everything your DNS cannot show. Send us one.

One domain can also be watched: subscribe with it and we re-read its authentication DNS daily, emailing you only when a record actually moves. Campaign preflight stays separate from published-DNS monitoring so neither can be mistaken for the other.