DMARC

DMARC (Domain-based Message Authentication, Reporting and Conformance) is a text record in your DNS that completes SPF and DKIM. It states your policy for mail that fails authentication: none (deliver and report), quarantine (send to junk) or reject (refuse). It also asks receivers to send you aggregate reports about who is sending mail in your domain’s name. Crucially, DMARC checks alignment: the domain in the visible From address must match the domain that passed SPF or DKIM.

It matters because publishing a DMARC record is now a baseline expectation for anyone sending business email in volume, and its absence is treated as a warning sign. It also matters for you: the reports show whether a forgotten marketing tool or a misconfigured server is sending on your behalf and quietly spending your reputation. Many teams start at none to gather reports, then move to quarantine and reject once every legitimate source is authenticated.

In Seegnals, DMARC status is shown per sending domain in the Deliverability tab, alongside SPF and DKIM, and refreshed hourly. The status is per domain rather than per mailbox, because the record lives on the domain and applies to every address under it.