Help

The free domain check, each of the thirteen checks it runs, and the records behind them - explained for somebody who has not met any of this before. Search it, or browse by feature or by concept. None of it needs an account.

Screens

One page for every screen: what it is for, what each control does, and what to do next.

The home page and the free check
Where you run the free domain check and read its result. No account, no DNS access, nothing to install.
The Why page
Who sends email pretending to be your domain, why they picked you, and the one thing this product does not stop.
The Pricing page
The three plans, which of their numbers the system actually carries, and which parts of the billing model are described but not yet running.
The Roadmap page
What is built, what is being built, and what is still an idea - which is also how to tell whether a feature you read about exists yet.
The legal documents
Four documents govern the service. All four are drafts pending legal review, and this explains what each covers.
Page not found
What the 404 page means and where to go from it.
The REST API reference
What the API is, how a token and its scopes work, and how to read the endpoint list - written for somebody who has not called it before.
The MCP server page
What the Model Context Protocol server is, what an AI client could do with it, and why there is nothing to connect to yet.

Features

What each capability does, why it matters, how to use it, and what it does not do.

The free domain check
Thirteen live checks against your domainâ€™s public DNS, with a plain-language finding for each. No account, no DNS access, nothing installed.
The thirteen checks, and what each one means
Every check the free domain check runs, grouped, with its own page explaining what it is, what going wrong costs you, and what to do.
The domain report
The whole check result as one document you can keep, forward to whoever runs your DNS, and show an auditor - on screen and as a PDF, from one template.
Domain resolves
Whether the domain exists in the public phone book of the internet at all.
Nameservers identified
Which company holds your DNS records, and therefore where you go to change them.
MX records
Where mail addressed to this domain is delivered.
SPF record
Whether you publish a list of the servers allowed to send mail using your domain, and whether that list is valid.
SPF lookup budget
Whether your SPF record stays under the ten-lookup ceiling the standard imposes.
BIMI
Whether you publish a BIMI record, which is what puts your logo beside your mail in inboxes that support it.
DKIM selectors
Whether we can find a published DKIM signing key for your domain at the selector names the common providers use.
DMARC record and policy
Whether you publish a DMARC record, and what it instructs receivers to do with mail that fails.
DMARC reporting address
Whether your DMARC record asks receivers to send reports, and where.
Subdomain policy and rollout percentage
Whether your DMARC policy actually covers your subdomains, and what proportion of failing mail it is applied to.
DNSSEC
Whether your DNS answers are cryptographically signed, so they cannot be tampered with in transit.
MTA-STS
Whether you publish a policy requiring other servers to use encryption when they deliver mail to you.
TLS-RPT
Whether you ask senders to report failed encrypted connections to your mail servers.

Concepts

SPF, DKIM, DMARC and the vocabulary - written for somebody meeting them for the first time.

SPF explained
The guest list: a line in your DNS naming the servers allowed to send mail as you, and the ten-lookup ceiling that quietly switches it off.
DKIM explained
The wax seal: a cryptographic signature on every message you send, which survives forwarding when SPF does not.
DMARC explained
The instruction: it ties SPF and DKIM to the address your reader actually sees, tells receivers what to do when they fail, and asks for a report.
Glossary
Every term used in the product and in this help, defined in a sentence.