Opening Stupid Windows WinMail.dat attachments with net-mail/tnef

I have a client that sends me files using Microsoft's propriety binary format (MS-TNEF MIME - Winmail.dat). I would see the text, but my claws-mail (sylpheed) is unable to view them. I'm primarily making this blog post so I don't forget how to do this in the future. Also, if anyone has a built in way for claws to open it, please let me know.

The only way that I currently know how to retrieve the embedded attachment is using net-mail/tnef. Here is the basic info:

[I] net-mail/tnef
     Available versions:  1.3.3 1.3.4 ~1.4.3
     Installed versions:  1.3.4(09:22:19 09/04/07)
     Description:         Decodes MS-TNEF MIME attachments

To open the attachement, save the attachment to a directory and execute the following command:

tnef --file=winmail.dat

This will extract the attachment and save it in the directory you ran the command. I'm sure there is a way to run this task from claws, but I'm hoping for a tnef plugin of some sort. So far, I'm not finding any support at this time.