Opening contacts from outlook 2003 in outlook 2007

This is a known issue with users sending PDF's using Microsoft Outlook. The link below gives instructions on how to change on their end.

Link:
PDF file changed to DAT file on receiving end when using Outlook in...

I also found a solution that might work on your end...This is from a blog post on the Apple forums.

This is a common problem.
I have found a converion web-site www.winmaildat.com, where you upload the problem file, and it is automatically 'deciphered', and the contents can be downloaded in their individual files.

.Dat file will be can be opend in Windows media player. if its not working there. please download and install vlc media player. then you will be able to open that file.

If these files are forwarded email messages, you can try this trick: save the .dat file to your disk, rename it with an extension .eml instead of .dat and then try to double click it. OE should open it in a new window.

However, if the .dat files are something else, you have to know what they are... Might try saving them and opening in Notepad to see if they contain anything familiar.

For the extend.dat, Microsoft does not have a solution yet. Please refer to the link below:

http://support.microsoft.com/kb/287844

Try the steps at the link below to solve the sent email issue:

http://support.microsoft.com/kb/287497

Log in to MSN Hotmail account. Then click on the Options button on the top right corner.

In the Options pull down menu, click on More Options link at the bottom of the list.

In the “Options” page, under “Customize your contacts” section, click on Export contacts link.

A file saving dialog will appear to allow you to save the contacts list file. Save the file on your computer.

Now open Outlook and click 'File'....'Import' and browse to the file you have saved from MSN....

This should import your contacts to Outlook

for dat u need 2 install windows synchronize 4.2 and windows outlook,,,,open outlook first and den connect mobile using data cable and den select contact 2 synchronize...dat will b saved 2 outlook...

The Extend.dat file is an information file created by outlook to store some small, usually useless information. It is located in a folder that's usually buried and hidden on most Windows PC's. Try this.

1. Close Outlook, and all other office related products.
2. Open your control panel.
   
3. Find the entry called mail. You may have to select the classic view on the left to be able to see this icon.
4. You should now see something like this image:
   
5. Click on data files. You should see something like this:
   
   
6. Now click on open Folder. This will take you to that secret and hidden place on your hard drive that contains you out data files. You should see a files called extend.dat in there. If you do, delete it and reopen outlook. If you don't, then you may have to destroy your outlook profile and recreate it.

Comment back here on if this fixedya, or if I need to help you recreate the profile. If I'm going to help you recreate the profile, you'll need to at a minimum know who your hosting your email through.

Steven

Outlook Express does not display any message attachments if TNEF-encoded file (winmail.dat) was received. If you are expecting some attachment, but do not see any, it still can be there.

To decode such a message perform the following steps:

1. Save the whole e-mail message to an *.EML file via File, Save As, or Drag-and-drop.
2. Open the *.EML file in a text editor such as Wordpad or Notepad.
3. Locate the line Content-Type: application/ms-tnef;, and change the Content subtype to something else, such as Content-Type: application/zzz;
4. Locate the line name="winmail.dat" and change to name="winmail.tnf". You may change the winmail part as well, if desired.
5. Save the *.EML file from the text editor.
6. Double click the *.EML file from the Windows File Explorer. This will open the message in a mail window and the TNEF attachment should now be available for saving.
7. Drag the saved attachment into the Winmail Opener program. Decoded attachments will then be there and can be dragged or opened.
   

You cannot open a data file this is only read by a programme or the operating system, but what may have happened is that you have been sent a file for which you do not have a programme for it to open with and windows has use the.dat as default. If you know who sent it and what file it is suppost to be, ask them what file it is eg a picture or video file and use one of your own programmes to open it using the right click and 'open with' method.