Janet UK, the organisation that operates the main network used by education and research bodies in the UK, is blocking 100,000 spam emails a month.

The government-funded group is using an appliance from security specialist Sophos to protect its gateway against email-borne malware attacks such as phishing.

Employees had been inundated with spam emails and productivity was suffering, said Peter Kent, head of IT services at Janet UK.

"On one user’s account, the appliance has blocked more than 150,000 spam messages to date, many of which would have slipped through our previous vendor's filter and caused serious productivity problems," he said.

"Now employees are benefiting from not having to read and delete unwanted mail while our IT administrators enjoy low-level maintenance."