In reconfiguring its email servers to block spammers, the Microsoft Network knocks out some members' email service.
Some MSN members also have been inadvertently blocked from sending mail through the MSN system, a Microsoft spokesman confirmed today.
On Thursday, MSN, the showcase online site for Microsoft, reconfigured its mail servers to stop accepting outgoing mail from non-MSN customers.
Many ISPs do the same thing to keep junk emailers from using their mail servers. Spammers often will look for open SMTP servers to relay their bulk email. The practice is known as hijacking, and antispammers for years have urged all system administrators to close down the servers to outsiders.
Microsoft reconfigured its servers so they would only accept mail from IP addresses belonging to MSN customers, a spokesman said.
Unfortunately, however, in the process of blocking out all non-MSN IP numbers, it blocked some MSN IP numbers as well. The spokesman said Microsoft had gotten the numbers from its access service, backbone provider UUNet. As a result, some customers were unable to send mail for several days.
Microsoft had contacted those customers to tell them how to make those changes, the spokesman said.
This is not the first time that MSN has had trouble with its email. Last year, MSN members experienced a few frustrating outages due to overburdened mail servers. MSN upgraded its service, along with its email, in October.