I do not know what is causing this problem and it just started occurring on 9-12-07.

It started with an associate in Houston sending me a photo. He sent me 4 separate email messages but each time, I received the email message but no attachment. The email was being sent from a corporate account and going to my ATT account. My email client is OE 6.x.

When I called ATT Tech Support, I was told that the attachment was a .DAT file. The rep could click on the attachment and it would convert to a jpg and display on the server............but neither Outlook nor Outlook Express knew what to do with.

Since I was on a deadline, I had my associate send the picture (attachment) to one of my web email addresses and I downloaded the picture from there.

Once I had the picture on my computer, I sent it to a friend, who is also an ATT customer. He was able to display it just fine. Obviously what I sent to him was the jpg file, which I had already saved on my computer.

Then last night, my associate in Houston sent me an email with a Word document attachment. Again, I got the email but no attachment, so I called ATT again.

The attachment on the ATT server was once again a .DAT file but this time I went out to ATT web mail site and downloaded the attachment from there and it was the Word document.

Then I called Tech Support trying to find out what was going on. This is what I find out from them.

1. The problem is starting on the sender side of the equation. It is either starting at the client's workstation or a server security product is converting the file to .DAT format before it is sent out.

If you've ever received a document sent from Outlook that is unreadable with a *.dat, or *.unk or *.tnf extension, the problem may be related to the person who sent the document.

This is a known problem related to Microsoft formatting. Microsoft has a proprietary format (MS/TNEF - Microsoft Transport Neutral Encapsulation Format) that can be set for outbound mail on Outlook clients. It is normally set by default on Outlook 2000 clients.

When a message containing TNEF information is received by a mail client that does not understand TNEF, there are three common results:

1. The plain text version of the message is received and it contains an attachment named Winmail.dat. The Winmail.dat attachment does not contain any useful information when opened since it is in the special TNEF format.

2. The plain text version of the message is received and it contains an attachment with a generic name such as ATT00008.dat or ATT00005.eml. In this case the client is unable to recognize the TNEF part of the message, and is unable to recognize the Winmail.dat file name, so it creates a file name to hold the TNEF information.

3. The plain text version of the message is received and the client ignores the Winmail.dat attachment. This is the behavior found in Microsoft Outlook Express. Outlook Express does not understand TNEF, but it does know to ignore TNEF information. The result is a plain text message.

This fix is simple, the end user must resend the document check the option to send attachements as Plain Text / HTML only. Refer to the following Microsoft instructions on how to change this option:

http://support.microsoft.com/default...b;en-us;196784


However - what happens if the person who sent the document can't (or won't) change to the standard format? You have two options:

Have them resend to a hotmail account. Hotmail is which is a Microsoft product that accepts MS/TNEF format. You'd have to set up and check hotmail.
Use the shareware fentun utility. (www.fentun.com) as described below. This option is only for Windows 95 or Windows 98 clients.


http://www.tencorp.com/salestip.nsf/...a!OpenDocument
When I brought this issue up with my Houston associate, he said that this was a ATT problem and not on his end because no one else has ever reported encountering this problem. It is really peculiar that this pjroblem goes away completely, if the mail is sent to a web mail address such as gmail or yahoo.

Has anyone else encountered this problem before? If you have, then what turned out to be the cause of the problem.

Cheers,

Linda