Symantec has announced it is buying anti-spam vendor Brightmail for $370 million in cash.

The purchase will complement Symantec's existing gateway-security products in the fight against spam, the company said. It requires regulatory approval but Symantec expects it to go through by July. It refused to disclose what effect the purchase may have on its accounts.

"Spam has increasingly become one of the most severe threats to individuals and enterprises today, topping viruses as the number one problem plaguing email systems and administrators," said John W. Thompson, Symantec chairman and chief executive officer. "Brightmail is the leader in helping enterprises, service providers and wireless carriers mitigate this threat."

Brightmail's president and CEO, Enrique Salem, said that "by joining forces with Symantec, we can provide our combined base of customers around the world with the broadest messaging security solution in the industry."

The announcement is just the latest in a series of moves in the security market as spam, and security in general, become bigger issues. From today, another part of the US anti-spam law comes into effect. Earlier this month, Symantec released updated email security software.

Symantec's traditional route out of its circle of complacency is to buy dynamic companies and slowly suck the lifeblood out of them, and Brightmail, it seems, it just the latest fly to fall into its web. Brightmail has often led the way with its technology and has won customers including Avaya, eBay, Cisco, Microsoft and Lucent on the back of it.

As such, Symantec gets a definite foot-up in what is becoming a mainstream issue. How long it takes to lose that advantage to another company that it subsequently buys is anyone's guess.