Why do I receive a file winmail.dat when other MAC devices get a regular attachment?

We were experiencing the same winmail issues. 4 imap accounts on outllook2011. They are all the same service provider. 1 rcvd winmail attachemnts while the the others all were ok when the file was sent at the saem time to all the accounts. We deleted the affected account in outllok2011 and added it back in. This fixed on all devices including the ipad. This was the only way we culd solve the problems. The RTF settigs were already correct on outlook2011 and 2013.

I was having this problem after my wife's company installed new Microsoft Software. Calendar invitations and some other attachments she sent to me were coming through as winmail.dat files on my iMac with Mountain Lion.

She deleted my contact and created a new one. Problem solved.

Microsoft. Need I say more.

Thanks, this suggestion solved my issue. I had been receiving any attachments that were sent from Outlook as winmail.dat files in Apple Mail. So, I deleted the email address that was cached in Outlook (I did not have a contact created for this email address), then resent the attachment from Outloook and received the correct attachment in Apple Mail.

THANK YOU!

This issue started suddenly for me along with me switching to an iPhone 6 AND me changing to an iCloud.com email account. I am NOT saying that these have anything to do with the issue, just things which happened all at the same time.

After speaking with Apple, we realized that I was NOT having the winmail.dat issue when the sender's OUTLOOK was turned off and he emailed me from his iphone and ipad... I received all emails with normal attachments.

SO…

We did the following:

• he deleted my contact card, and I deleted his
• he logged OUT of Outlook, and then back in
• I deleted all of the winmail.dat emails from my Apple Mail
• he signed back in and sent me a word doc, pdf, excel sheet and photo
• we both added back the contact cards
• all now work

We have learned that there was update in the OUTLOOK Exchange server that caused this issue. This is NOT an email or Apple issue.

Hi ,

The person that is sending you emails, has chosen in Outlook, to use the RTF format, for emailing and or specifically for emailing you. Perhaps this is default Outlook behavior at times.

This results in the winmail.dat file, which is the RTF format, of the attachments that were intended for you.

If the user would configure Outlook, to use the HTML (web) format, for emails, then you would receive the attachments as intended. As well as anybody else.

Apple mail and other mail systems, do not understand the RTF (rich text) format, and probably have to pay Microsoft licensing fees, to be able to use this format.

The options, for setting this in Outlook, differ for different versions of Outlook, but are found generally under

Tools > Address book, for setting a specific person to , use HTML format, and not RTF format, that persons email.

Also, under "Tools" > "Options", > "Mail format", for setting that all emails, will use the HTML format, instead of the RTF format.

More info

http://support.microsoft.com/kb/278061

So wonderful for a simple (yet elusive) solution to my problem! Now my husband will once again have an updated calendar and not excuse for not knowing what family plans are :-)

since that did not help me I wonder if it has been working for you.

My wife has MacBook Air, 2012. El Capitan. Reads Windows mail with PDF attachment perfectly. I had a MaxBook Pro ('09) and worked fine. I just bought the MBP "13 with Retina and cannot read my emails sent to me from the same office machine. Comes as winmail.dat.

Both machines are on same level. The only thing I can imagine that there was something on the upgraded machines that is now not on my original El Capitan (this was never upgraded, came with EC).

Now, I also want to note that I need somebody less intelligent than the level 10 arrogance, but somebody who is more constructive.

I know this question was posted a long time ago, but I had the same problem and found this forum when looking for a solution. I get emails from one particular company whose attachments always come through as winmail.dat files. Whilst I have not worked out how to stop them arriving like this (which is what I was looking for when I found this forum), I have found a work-around to view them. I simply save the attachment (on the Desktop or wherever is convenient) and then click on the icon so that I can change the file name and then change from winmail.dat to winmail.pdf. I can then open it with Preview. Hope that helps some people because I know it was driving me mad!

This appears to only work if the only thing in the .dat file is a single pdf or jpg.