Microsoft Corp. said Friday that some people who use its Hotmail and MSN e-mail services are not receiving e-mail sent from Comcast Corp. accounts and other Internet service providers.

Brooke Richardson, a group product manager with Microsoft's MSN online division, said the problem appears to be due to an increase in e-mail volumes, which it is attributed in part to the Sober Internet worm.

She said the high volumes are causing e-mail to either be delayed or not make it to MSN and Hotmail users at all.

Richardson said the problem began earlier this week. She would not name the other Internet service providers besides Comcast whose users were encountering the same problem. She also couldn't say when the problem would be fixed.

Comcast spokeswoman Jennifer Khoury said the problem is only affecting Comcast e-mail being sent to the MSN and Hotmail accounts, and that other e-mail is getting to recipients without delay. She said the company is working with Microsoft to resolve the problem.