Unfortunately, this application has a goofy name which is TNEF’s Enough. Mac users can open the winmail.dat file using a free application (donations accepted) and extract the files hiding inside. Update February 2017: In November 2015, an iOS version of TNEF Enough was released by the developer of TNEF Enough. Update May 2012: If you need to open winmail.dat files on your iOS device (iPhone, iPad or iPod Touch) try Winmail File Viewer which currently costs 99 cents in the iTunes Store. Under certain circumstances Outlook will encode attached files, like Word or PDF files, in this winmail.dat format. Winmail.dat files are sent by people using Microsoft Outlook as their email application. Did you receive an email attachment named winmail.dat or winmail? Here’s a brief explanation of what this file is and instructions for opening it.
