UK census finds reporting records still naming retired Mail Check

What changed

A Servnet study published on 19 September 2026 found UK public-sector email reporting records still naming the retired NCSC Mail Check service. Its snapshot of 907 organisations counted 107 DMARC records and 284 TLS reporting records with a Mail Check address. These groups overlap; the figures should not be added together as a count of affected organisations.

The study covers councils, NHS bodies, universities, police forces, and fire and rescue services. It measures published configuration, not whether reports reach an active monitoring system or whether mail is protected in practice.

The retirement happened in March

NCSC announced the retirement on 6 November 2025 and closed Mail Check on 31 March 2026. It confirms that users no longer receive findings from the service. The September development is the new measurement of remaining references, not a new shutdown deadline.

Existing government email guidance calls for DMARC and TLS reporting with regular review of the data. Its older recommendation to sign up for Mail Check predates NCSC's retirement notice.

What administrators should check

Review reporting destinations in each domain's _dmarc and _smtp._tls TXT records. Where a destination names mailcheck.service.ncsc.gov.uk, confirm that a replacement reporting service is configured and receiving current reports before removing the retired destination.

Keep other valid reporting destinations in place. Changing where reports are sent is separate from changing a DMARC enforcement policy or an MTA-STS policy. MSPs should check every managed domain and confirm who reviews the replacement reports.