Google's Postini division is changing how it sells security services for antispam, antivirus and e-mail archiving to appeal to small and midsize enterprises that want lower entry costs, not expensive bundles.

The Postini services are being segmented into three basic packages called Google Message Filtering, Google Message Security and Google Message Discovery, says Scott Petry, director of product management at Google. "By breaking up the services, we are going to lower the prices for a lot of businesses," Petry says.

Google today has about 40,000 businesses and 14 million users using Postini services, but the goal is to gain a wider customer base by having more fine-grained services based on lower per-user fees, according to Petry.

(Compare antispam products and antivirus products.)

The Google Message Filtering service for filtering out spam and e-mail-carried malware costs $3 per user per year. At $12 per user per year, Google Message Security includes Google Message Filtering and added elements such as content-policy management to check for compliance violations.

Google Message Discovery builds off Google Message Security and adds a year of message data archiving, retention and discovery; it costs $25 per user per year for one year of archived data.

"Formerly, this would have been about $100 per user," Petry says. In general, Google is lowering the entry price for its Postini security services from about $30 per user to $3, according to Petry.

Google acquired Postini last year for approximately $625 million.