Extract Transport Neutral Encapsulation Format

Download and install the latest version of Filestar.
Right click on one or more Dat file(s) on your desktop and select Convert with Filestar.
Type extract in the search box.
Press Extract.

What is .dat?

Name: Transport Neutral Encapsulation Format
Extension: .dat
Format: Binary
Category: Other
Developer: Binary Research Limited
Description: The .dat file type is a data file in the Transport Neutral Encapsulation Format (TNEF). This file type is commonly used by Microsoft Outlook and Exchange to encode email attachments, and contains the message body, subject, and other email properties.
MIME Type: application/octet-stream
Wikipedia: .dat on Wikipedia