A lab, not a funnel.

EmailAuthLab is a free, public lab for testing and understanding email authentication. Send a real message to a private test address, or paste a message's headers, and see exactly how SPF, DKIM, and DMARC judged it: what passed, what failed, why it matters, and what to change next. Clear enough for anyone, detailed enough for mail admins.

Built by TrustYourInbox

EmailAuthLab is built and operated by TrustYourInbox, a DMARC monitoring product for small businesses and MSPs. We say that plainly: this is a free learning and testing tool, sponsored by a company that sells DMARC monitoring. It has its own look, but it never pretends to be an unrelated third party.

The free experience is never gated or degraded to force a signup. There is no account, no email capture, and no trial clock. A test tells you how one message did at one moment; when you need ongoing visibility across every sender over time, TrustYourInbox is the natural next step. We earn that handoff; we do not extort it.

What we keep, and what we never keep

Test results store the verdict only. We never keep message bodies, subjects, or attachments, we show domains rather than full addresses, and results expire on their own or the moment you delete them. Headers pasted into the analyzer are processed transiently and never stored. The details are in our privacy policy.