DAT files received as email attachments can be opened using specialized apps or services such as Winmail.dat Explorer or the Winmail.dat Viewer website.

Global file systems aggregate data into a single hybrid cloud from multiple locations using object storage with access that satisfies traditional application needs, like file locking ...

I had tried converting the file to mpeg but it hardly compressed the file. What are the various file formats which can reduce the size of the dat files without deteriorating the picture quality?

If the DAT file you're trying to open is text, you can convert the file into text in the Microsoft Excel program by first saving it as a CSV file.