Director of product marketing Andrew Lochart said the company will shortly announce the opening of its European headquarters in London, is seeking channel partners, and will add two data centers, in London and Amsterdam, from which to run its services.

We’re not blind to the fact that there’s a lot of competitors out there and that every company in North America is on their second or third spam filter, he said. Europe, he estimated, is facing the scale of spam problem as the US did two years ago.

In Europe, particularly in the UK, Postini expects to face off against fellow managed service provider MessageLabs Ltd, and to a lesser extent SurfControl Plc. MessageLabs is clearly going to be our number one competitor over there, Lochart said.

The move comes as email security firms seek to secure market share and to evolve their products beyond simple anti-spam, before the expected market shake-out and consolidation that could come when the market saturates and spam declines.

Postini is currently at about 4,100 customers. Midway through the year, the company was at about 3,600, having added 750 in the second quarter. The company is on track to have more than doubled its customer base over the course of 2004.

Growth is probably plateauing, 66% of our customers are coming away from some other spam solution, Lochart said. We’re at a stage in this market where we’ve reached a certain level of saturation and there’s not as many green-field opportunities.

Companies face the choice between managing their own filters or outsourcing to the likes of Postini, MessageLabs or FrontBridge. Rivals in the software and appliance space are also grabbing share, and competition is forcing prices down.

Recently, Cloudmark said it will start offering a year’s free license to customers moving from another vendor. Tumbleweed, one of the few public-listed email security firms, acknowledged in its last conference call that prices are declining.