Active Cyber Defence

The NCSC programme tackling cyber attacks in a relatively automated and scalable way, to improve national resilience.

NCSC Mail Check

Mail Check is the NCSC’s platform for assessing email security compliance. It collects, processes and analyses DMARC reports from across the public sector.

An update on central government progress on adopting good email security practices.

A guide for IT managers and systems administrators intended to help secure your organisation's email in two distinct ways.

An introduction to Mail Check - a freely available service to help public sector email administrators improve and maintain the security of their email domains.

Active Cyber Defence - one year on

A paper written by Dr Ian Levy, Technical Director of the NCSC, following a year of the Active Cyber Defence programme.

Ian Levy discusses a new academic paper which shows how UK citizens are safer in cyberspace thanks to the ACD programme.

Results of the NCSC's Active Cyber Defence programme have been revealed in figures published today.

An introduction to Web Check, the NCSC's new service that helps you to find and fix common vulnerabilities in UK public sector websites you manage.

Four ‘Active Cyber Defence’ programmes will help to immediately improve basic cyber security across UK business and government departments.

UK Public Sector DNS service

The UK Public Sector DNS service is now live - here is what it is and how to use it.

Ian Levy explains why the NCSC asked Nominet to build this critical service.

Simple steps so your organisation can use the new UK Public Sector DNS services.

Web Check Findings example screen shot

Introducing Web Check — a service that helps you find and fix common vulnerabilities in UK public sector websites you manage.

Get Started

Active Cyber Defence programmes that will immediately help to improve basic cyber security across the public sector, at scale.

Web Check

Web Check — a free-to-use website configuration and vulnerability scanning service, available to all UK public sector organisations.

It is simple to use - first you create your own 'watch list' of website URLs you manage. Then Web Check runs a growing set of non-intrusive scans and reports its findings to you.  You can share your URLs and findings with colleagues and annotate findings for future reference.

Find out more about Web Check.

Mail Check

We’re encouraging and tracking adoption of email security standards across the public sector.

For advice on how to understand and improve your email security please read our latest guidance on email security and anti-spoofing here.

Mail Check, a free tool available to all UK public-sector organisations, assists with email security configuration and reporting – find out more here.


The National DNS service provides the UK public sector with two reliable DNS resolution services that protect users from threats posed by known, malicious malware.

The service is available to all UK government and public sector organisations, via the internet (available now) and via the Public Services Network (PSN) (available soon).

Find out more about the National DNS service.