What is a winmail.dat file?

What is Winmail

Winmail.dat files are attachments sent by Microsoft mail applications (Outlook, Outlook Express or Exchange) on a proprietary format called TNEF (transport neutral encapsulation format). Being a non-standard attachment format, users from other e-mail clients (like Gmail or Thunderbird) or platforms (like Android, Apple, iPad or iPhone) cannot natively read them.
An e-mail containing an winmail.dat attachment looks like an empty e-mail with only one attachment. The original e-mail information like subject, body and attachments is packed into a single winmail.dat file, which in some cases also receives a generic name like ATT00001.dat or ATT00005.eml.

What is a winmail.dat file?

How to open Winmail.dat files

Winmail.dat Reader is the only free application that decodes not only the embedded attachments but also the subject and body. It comes in three version:

More information on what is a winmail.dat file

To learn more about winmail.dat files, check also these links:

Other native decoders

If you are looking for a Mac, iPhone, iPad or Linux solutions, check these ones:

What is a winmail.dat file?

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