It's sad that every modern advance seems to be counterbalanced by a setback.

The invention of the automobile led inevitably to traffic jams. The convenience of commercial flight, is tempered by airline food. And, although e-mail may have revolutionized the office, many users find themselves devoting more and more time to deleting unsolicited marketing messages known universally as spam.

Every day the spam pours in.

There are the seemingly innocuous offers of cheap printer cartridges and weight loss products, the medical procedures that promise to add "at least five inches" to your sex life and the e-mails from "Jenny" who claims to be your long-lost friend but turns out to be a link to a pornographic Web site that bombards your monitor with hard-core images until your office colleagues write you off as a pervert.

Service providers such as MSN and AOL provide rudimentary spam filters, but they are generally not customizable and are tailored for the personal e-mail accounts of their customers rather than the wider business environment.

Some almost free software can be downloaded from the Web at www.mailwasher.net. It's what they call shareware. You can download it for nothing and, if you like it, you can send some money to its author Nick Bolton in New Zealand.

But Mailwasher has its limitations. Although it highlights the messages that most likely carry viruses and allows you to blacklist repeat offenders such as anybody@OfferMagnet.com, there's still the daily stack of spam giving phony addresses at zApfnwKFcn.com and every other possible combination generated by some untracable computer. The daily routine of mass deletions is streamlined but it's still a chore.

Now a company based in Chula Vista, called BiggPipe Internet has launched a service that it claims will help businesses combat spam and viruses in the workplace.

It's called Clean Mail and it uses a set of 30 rules for testing the integrity of an e-mail. The results are then used to label the e-mail as valid or spam. If spam, the message is not delivered and a report is generated. The administrator of a domain using Clean Mail has complete control of the system.

If too much unwanted e-mail is getting through, the administrator can use a Web-based control panel to increase the sensitivity of the system. If legitimate e-mail isn't getting through, the sensitivity can be decreased. Its cost starts at about $1.50 per month per e-mail address in the covered domain.

The service is available to any valid domain regardless of service provider or hosting location. For more information, call 421-2706 or browse the Web site at http://cleanmail.biggpipe.com.