The company already offers software and appliances for premises-based spam and virus filtering at the gateway, desktop and mail server. Adding Hosted Mail Security means it now also gets to directly touch many of the emails it filters, potentially improving the technology.

The hosted market has seen rapid growth over the last couple of years, with young firms such as Postini, MessageLabs, BlackSpider and FrontBridge already serving thousands of mid-size companies.

Symantec becomes the second big name security vendor, after VeriSign, which partnered with FrontBridge. This allows these smaller firms to claim the market has been validated, whilst also increasing the pressure in an already competitive market.