It is not yet clear what caused the problem, said AOL spokesman Rich D'Amato. "What's important is that the mail is flowing again," he said. "AOL and MSN together are trying to determine what the problem was and where it occurred."
The problem, said Marco DeMello, program manager for MSN's email system, began November 23, just a week after the most recent AOL email outage. DeMello said the problem can affect the 325,000 members who use MSN 2.5.
D'Amato yesterday said he had not been aware of the problem but was looking into it.
DeMello said he tried several times to reach AOL executives by both phone and email to discuss the problem but has been unable to get a response.
"I notified them of this problem last Wednesday and I notified them again over the weekend," he added. "I even called the network data center and talked to them. They said they were going to look into it and get back to me, and they didn't."
But after press inquiries, AOL and MSN did make contact.
MSN members had been complaining that they were unable to send email to AOL users, according to DeMello. Many also sent email to CNET regarding their problems.
DeMello said he has thoroughly checked MSN's system to see if the problem was on his side, but he is convinced it isn't. He's not interested in laying blame, he noted; he just wants MSN members to be able to reach their friends on AOL.
"There's nothing MSN can do. I wish there was. The ball's in [AOL's] court. We would do whatever it takes [to fix it]."
DeMello added that without communication, he can't be positive about the problem, but he thinks he knows what happened. After AOL's most recent outage, when the online company brought its system back up, it may have brought an outdated copy of the tables that route addresses to their destinations. The old tables did not recognize the domain name for the mail from MSN's newest service, he said. That domain is only a few months old.
It would be tantamount to a company losing its current phone book and instead using last year's version.
An MSN spokesman said today that DeMello's theory was accurate. D'Amato yesterday said the theory was wrong, but today said that an investigation would show what the cause was.
When MSN 2.5 members sent email to AOL, they got back messages saying their mail could not get through to its destination. At least one user speculated about the nature of the problem: "AOL has been rejecting mail from MSN since the weekend. Now maybe it is rejecting other mail from other systems, but maybe this is not a technical problem--just a political one."
But DeMello said he was sure the problem was technical. It would not benefit either company to block mail, as both would get complaints from users. MSN in the past has been careful not to gloat over AOL's problems, primarily because gloating has a funny way of coming back to haunt the gloater.
MSN has had plenty of its own email problems in the past. A good portion of the service upgrade in MSN's 2.5 version focuses on email.
In fact, AOL apparently thinks the new email client is good enough to use itself. Yesterday, coincidentally, AOL announced that it is incorporating portions of the same Microsoft technology into its own system.
America Online said it will integrate Microsoft's Outlook Express email technologies, including dynamic HTML, into its existing email client. AOL also ships its software with Microsoft Internet Explorer.