Reading winmail.dat files sent to Apple Mac users

By Grant Jacobs 03/04/2013

Tip: an easy solution is to forward the mail to gmail.

Files sent by Microsoft Outlook users can have contents received by Apple Mac recipients as an attached winmail.dat file – that they can’t read.


Many on-line forums offer possible solutions to this problem. You could ask the sender to please send mail to you as either plain text or HTML-formatted email, not RTF, but many recipients will not want to pester an important client, boss or whatever this way! There are some programs (mostly commercial software) that claim to read these files, but successful results appear not to be a sure thing. Similarly, there are web services offering to convert these winmail.dat files if you upload the file to their site (with obvious security issues).

An easy solution if you don’t receive too many emails with winmail.dat files is to simply forward the message to your gmail account, log-in to gmail and read it there. Gmail will handle the contents correctly. You can also download the converted file if you need a local copy, for example to add an event to iCal.

This solution doesn’t seem to be mentioned as much – hence this short post.

I have to admit I would like to see Microsoft write a plug-in for Apple Mail to handle this. After all, the issue (apparently) stems from their propriety TNEF format (Transport Neutral Encapsulation Format), but given the time that has elapsed I suspect that’s not going to happen.


My one attempt suggests forwarding the message to a gmail account that is then automatically forwarded back to the Mail account doesn’t resolve the issue. A shame, as it’d avoid having to log into Gmail.

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0 Responses to “Reading winmail.dat files sent to Apple Mac users”

    • I was aware of TNEF’s Enough – lots of people suggest it, but if you read around you’ll find people have mixed results with it. It didn’t work for me either.

      Few people (relatively speaking) seem to realise that gmail can solve this problem, hence the post. If you are already using gmail, there’s no need to download or install anything – just send the offending email to your gmail account.

  • Worked really well! I also had problems with TNEF’s Enough, but your method is so easy and simple. Thanks Grant.

  • I like the Gmail option: I’ve never heard of that one before.

    I’m surprised that Apple hasn’t incorporate winmail.dat support into something like Preview; sure, it’s not “their problem”, but then again neither is our need to view PDF files, Excel documents, etc.

    That said, there are literally dozens of apps available to open winmail.dat files. I’m partial to LawBox’s Winmail DAT Viewer on the Mac on iOS, but, as I said, there are many, many choices.

    Go with the one you trust.