Install tnef by entering the following commands in the terminal:
sudo apt update sudo apt install tnef
Description:
Tool to unpack MIME application/ms-tnef attachments
TNEF is a program for unpacking MIME attachments of type "application/ms-tnef". This is typically a Microsoft only attachment. . The TNEF program allows one to unpack the attachments which were encapsulated into the TNEF attachment, thus alleviating the need to use Microsoft Outlook to view the attachment.
Homepage: https://github.com/verdammelt/tnef
Version: 1.4.12-1.2
Section: universe/text