Title: Extract files from winmail.dat
       Author: Solène
       Date: 02 May 2018
       Tags: unix email
       Description: 
       
       If you ever receive a mail with an attachment named "winmail.dat" then
       you may be disappointed. It is a special format used by Microsoft
       Exchange, it contains the files attached to the mail and need some
       specific software to extract them.
       
       Hopefully, there is a simple and effecient utility named **tnef** to
       extract the files.
       
       Install it: `pkg_add tnef`
       
       List files: `tnef -t winmail.dat`
       
       Extract files: `tnef winmail.dat`
       
       That's all!