Your organisation relied on NCSC Mail Check for DMARC reporting — the service was fully retired on 31 March 2026, and the reports and dashboards are gone.
The UK's National Cyber Security Centre retired Mail Check (and Web Check), explicitly recommending that organisations move to commercial DMARC monitoring. Around 17,000 UK public-sector organisations — schools, councils, trusts, small public bodies — lost their free aggregate-report visibility, while UK government guidance still requires DMARC on public-sector email.
rua= tag at a replacement monitoring service — until you do, nobody is reading your reports and new sending problems go unnoticed.p=none, use the fresh reports to finish the journey to p=reject — that was always the point of collecting them.DNS changes propagate within minutes to 48 hours. Mailbox providers pick up the new records on their next check — most senders see bounces stop within a day of correct configuration.
Formal enforcement targets bulk senders, but partial authentication already costs you inbox placement at every volume — and spoofing protection matters regardless of how much you send.
Hosting support can add DNS records for you, but they don't know which services send as your domain. You (or a monitoring tool reading your DMARC reports) have to provide that list — that's the actual hard part.