The longest running Mac solution for
"winmail.dat" files. No cost and no in-app purchase to use!
TNEF's Enough allows Macs to read and extract files from Microsoft TNEF files. The files are usually received via email from Microsoft Exchange and Microsoft Outlook users. Standard e-mail programs will receive the TNEF file as an attachment named "winmail.dat."
The "winmail.dat" file can contain attachments, contact files (.vcf) or calendar files (.ics) as well as a rich text or HTML version of the email body. TNEF's Enough can open the "winmail.dat" file and allow you to extract the attachments.