Clearswift capitalises on email filtering opportunity

Some companies are tipped for greatness the moment they are launched. At others, the founders can toil for years before hitting upon the perfect formula or even realising the value of what they have created.

Clearswift falls into the latter category. It had been building systems for major customers such as the UK Ministry of Defence for almost two decades before its founders


Company: Clearswift

Main activity: Content filtering software

Founded: 1982

CEO: Don Taylor

HQ: Theale, UK

Status: Privately held. Clearswift has received $40 million in two rounds of funding. The second tranche of $30 million helped to finance the acquisition of the Mimesweeper and Pornsweeper monitoring tools from Baltimore.

Revenues: Not disclosed.

Key competitors: Brightmail, SurfControl, Symantec, Websense and Webwasher.

Infoconomy comment: Clearswift’s opportunistic purchase of MimeSweeper from troubled Baltimore Technologies has helped it to market leadership in content filtering. However, the company’s products are relatively niche, and will be regarded by many organisations as something that should come as part of a broader security suite.



recognised the wider appeal of one of its products – a content filtering application for monitoring and managing corporate email content.

EnterpriseSuite, aimed at large multinationals, is made up of three core components. ClearEdge provides email content filtering by breaking down the message into its constituent parts (body text, subject, attachments and so on). It then applies proprietary text analysis techniques to determine whether the email can be allowed in or out of the organisation, unzipping compressed files when necessary.

Alongside it sits ClearSecure, an encryption engine for securing internal messages; and ClearPoint PMI, a central console that enables systems administrators to set and enforce rules based on corporate email policy and users’ authorisation levels.

As well as blocking potentially harmful emails across the organisation, Clearswift’s content filtering technology can selectively prevent individual sensitive documents from being leaked out, claims Clearswift CEO Don Taylor.

Supplementing this high-end focus, the company acquired a second, closely related product line in early 2002. MimeSweeper, formerly owned by Baltimore Technologies, is a low-end email monitor that runs on a Windows server.

Another Baltimore product, PornSweeper, has been extended and renamed ImageManager. As well as identifying pornographic email attachments and detecting employee access to sex sites, the product now can create ‘fingerprints’ of selected images so that their transmission can be restricted. Clearswift intends to add this function to EnterpriseSuite.

But while Clearswift can today boast market leadership in content filtering, 12,200 customers and 11 million end-users worldwide, the company’s niche products will be regarded by many organisations as something that should come as part of a broader security suite.

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Ben Rossi

Ben was Vitesse Media's editorial director, leading content creation and editorial strategy across all Vitesse products, including its market-leading B2B and consumer magazines, websites, research and...

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