Hospital e-mail filter can weed out drug spam

Hammersmith Hospitals NHS trust has installed a spam e-mail filter which the manufacturers say is sophisticated enough to tell genuine medical e-mails from pharmaceutical spam.

The Messaging Security Gateway MLX system, supplied by Proofpoint, examines the structure and content of all emails that arrive on the hospital trust’s servers, and flags them as spam if necessary. Around 100 spams are caught every hour, according to the company.

Mathew Williamson, head of networking and technical support at Hammersmith Hospital, said: "We have been pleasantly surprised at how little administration is required and the results speak for themselves. Virtually all spam has been halted before reaching employees."

Keith R Crosley, director of corporate communications at Proofpoint told E-Health Insider: "In essence, the MLX engine is a very complex model of email communications. It’s not just looking for keywords – for example ‘Viagra’ – to identify spam. Much like a human reader of email, MLX understands that the presence of a reference to Viagra in the context of a sales pitch might represent spam but that there are also legitimate medical communications that may contain the term Viagra. No one attribute decisively identifies that a message is spam."

Crosley said that it operated through an advanced version of Bayesian filtering, where a score is calculated from various keywords and structures common to many spam e-mails. "The methods we use are rather more advanced. In particular, Bayesian approaches don’t understand the dependencies between different ‘features’ found in an email message."

The system was installed following continual complaints from users about "unsolicited and offensive" e-mail blocking their inboxes. It uses a filtering and learning system with around 100,000 different criteria for telling apart genuine and unsolicited commercial e-mail messages. The company says that there have been virtually no false positives since the system was installed.

Gary Steele, CEO of Proofpoint, said: "The Proofpoint Security Gateway provides a scalable solution this is ideal for healthcare organisations like Hammersmith, as it offers complete protection from spam and viruses while also enabling compliance with healthcare-related privacy laws."

Proofpoint is based in Cupertino, California, and was set up by a former Chief Technology Officer of Netscape. The company says the system was installed in one day by their London-based agency Data Integration.