I received an email today from a user with Outlook. The email contained an attachment called winmail.dat. I tried to figure out how to view it in Thunderbird, and I couldn’t figure it out. I finally was able to view it online in GMail.
First, I tried to install the LookOut extension, but it didn’t work. I am guessing it doesn’t support new versions of Outlook. I don’t know.
Then, I tried TNEF. You can install it with “sudo apt-get install tnef”. I downloaded the winmail.dat file and ran “tnef winmail.dat”. The response was “Seems not to be a TNEF file”.
In synaptic, I noticed another program called ytnef. I tried that: “sudo apt-get install ytnef”. Again, “ytnef winmail.dat”. Reponse was “ERROR: Signature does not match. Not TNEF.”.
Finally, I checked my mail online with Gmail, and it displayed the embedded image without even complaining about a winmail.dat file!
Sorry that is not much help, but it solved the problem for now. Please comment if you know another solution.