While it doesn't make cure-all claims, the company does state that its filter "allows individual members to restrict the flow of unsolicited email."
The online service is only the latest player to get into email filtering. Many Internet service providers as well as private software companies offer products that claim to curb incoming spam.
CompuServe, whose sale to online giant America Online is pending, will not disclose how its filter functions.
"We won't divulge the specifics of how the filter works any more than a bank would disclose its security system, but it has an excellent success rate in restricting spam," CompuServe's email manager Teemu Kolehmainen said in a statement. "Personal email will not be affected by this filter."
It is impossible to evaluate the company's claims without knowing more about the filter. But if it is true that personal email won't be affected, CompuServe is unique or at least exceptional in that regard.
With the problem of unsolicited junk mail seeming to grow daily, companies are scrambling for solutions that will please a customer base increasingly impatient with spam.
Many have chosen simply to take a list that AOL publishes as part of its spam filter, PreferredMail. AOL maintains a list of domain names that it blocks unless members go into special controls and turn off the filters for their accounts.