OMiC 1.7.7 - Winmail.dat Decoding Mac OS X Mail Add-On

OS X en iMac
Vía Flickr por el usuario William Hook - CC BY-SA.

OMiC makes Mac OS X Mail handle winmail.dat inclusions as if it had invented them, making included files and rich formatting available just like other attachments.


  • OMiC adds ms-tnef winmail.dat attachment handling to Mac OS X Mail.
  • All files included in winmail.dat attachments appear under "Attachments" ready for use.
  • OMiC converts Outlook meetings and tasks for use in iCal and contact information for Address Book.
  • OMiC supports Mac OS X 10.3/4.

Guide Review - OMiC 1.7.7 - Winmail.dat Decoding Mac OS X Mail Add-On

Of course, you shouldn't be getting winmail.dat attachments at all. But once they're in your Inbox, Mac OS X Mail should be able to deal with them. Unfortunately, all it shows you is winmail.dat and no way to decode its contents. You can save that winmail.dat attachment and process it with an external tool, of course. But is that convenient?

OMiC is very convenient — because you will hardly notice it. Winmail.dat attachments still appear in messages, but so do all the files normally hidden inside them. They're neatly lined up under Attachments, as well they should be.

OMiC extracts the richly formatted message parts (also hidden inside winmail.dat) as well and makes them available as RTF files which can be opened in TextEdit, for example. Showing them in the message area as the rich-text alternative might be even better, of course.

As far as attached files go, nothing seems to catch OMiC off balance. It can even extract and make available forwarded emails and converts Outlook's appointments and schedules for easy use with iCal.