Service is restored to the more than 200,000 users of AT&T's WorldNet Internet access service that were hit by an email brownout for nearly 24 hours.
AT&T said Saturday that about 50,000 customers were unable to receive email beginning mid-day on Thursday until late Friday evening, although subscribers were able to send email. Earlier reports had the number of affected customers at more than 200,000.
The email brownout was related to a hardware glitch in a database server that stores the service's email, according to AT&T spokesman Mike Miller.
Customers affected by the mail failure will receive a 30-minute phone card, worth about $10.50, or a credit of a half-month of standard service on AT&T WorldNet Service.
Email outages at online services and Internet providers not only cause public relations nightmares for the companies, but they anger users, who are becoming increasingly dependent on email to communicate. They also confirm worries by many analysts that the network is getting strained under increased use and must be upgraded.
In September, just two weeks after Sprint launched its Internet service, about 100 to 150 customers found themselves locked out of cyberspace during a five-hour intermittent outage.
The problem was traced to a database that served as Sprint's authentication server, Sprint executives said.
That glitch came in the aftermath of a 19-hour blackout by America Online in August. Many AOL users were frustrated, if not infuriated, by the incident.