dat extension

.dat files are binary (data) files created by any number of different programs. Some can be opened and read as text files using Notepad. Others can't. All you can do is try.

Asusming Windows here...

First, make sure whoever sent you that mail meant to attach a .dat file.
Next, if they did mean to, why? What program is supposed to use it?
If you want to safely open it, save it to a temp file somewhere (Windows temp folder will do) and open it using a right-click then "open with" and choose Notepad.
Scan it with a virus scanner first!

HTH
Nikki

Hello,

I don?t know the context of your question, but sometimes we receive .dat attachments in MS Outlook, and I'm assuming this is the situation. This is a problem within outlook, you are not meant to open this .dat attachment. If you search at MS KB in www.microsoft.com/technet you'll find information about this. This has to do with the way the sender and the receiver are viewing the emails, Plain Text, RTF or HTML.
Either way the solution is not opening the .dat file, is making sureyou receive the correct file format.

Hope this helps.

Thank you for all answers. This is an attachments from notes email I received from few customers. I do not know what email they use. If I detach and open through notepad, it is a garbage, i saw just a few word.
Thanks.

We have experienced this with Outlook 2000. This is an email text format issue. Senders should use plain text (Outlook - tools menu), not html formatting. Other than notepad .dat files are difficult to open. I have had momentary success with Conversions Plus software using their attachment wizard but it is unpredictable in results. The best bet is to send/receive in plain text or rich text at most. This will eliminate many attachment woes.

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