“This simple technical innovation could enable millions more people to join our mission to stop scam emails from ever reaching UK inboxes.”

The Report Phishing feature can be added to Microsoft’s Outlook email client.

However, it is currently only available with the corporate or business versions of Office 365.

Mike Cherry, the Federation of Small Businesses national chair, added: “Innovations like this are crucial to calling time on business crime. Small achievable steps will go a long way to protect thousands of small firms from cyber attacks. Every year, there are almost four million cases of cyber attacks against small businesses in the UK, and more than 50 per cent of these come from phishing.

“We’d encourage as many small firms as possible to look further into this NCSC tool and see how they can implement it to protect employees as well as businesses from harm. And anyone can take part, any small business, employee or self-employed person can forward attempted scam emails to [email protected]