Help with winmail.dat file attachment from 2 senders...

Michael Katz
Michael Katz used Ask the Experts™
Emails coming in with winmail.dat

I have put sooooo many hours into trying to figure out how I can use Microsoft Outlook on a MAC.. and not get this as an attachment. I have repeatedly asked the 2 senders that this happens with their sender preferences and they can't do it...What am i doing wrong?

I am using an Office 365 subscription version 15.31 (170216)

Is there anything I can do?? Please help
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JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Quote from an article I saw "The Winmail.dat file is used to preserve Rich Text formatting. Outlook uses it when sending a Rich Text-formatted message"  

I have not seen a winmail.dat file in a Windows world for years. Outlook (Windows) uses Word for its editor.

Try sending in straight text (not HTML) and see if the problem goes away.


I haven't seen it in years either..I am not the sender.. I am the recipient..The 2 senders keep telling me they have done all they can and if they send me an email they need to change there preferences for me.. and then change them back for everyone else

The settings has to be preferably done on the server level:

It becomes a problem though if it's not their own server, but from their ISP or mailhoster, who usually are not very responsive to adjust server level changes.
as far as i remember this happened with old servers configured to use the TNEF format which uses RTF for rich text rather than html embedded in mime. one of those numerous times when m$ tried to impose their own format on everyone else, and one of the few times they failed entirely... to the poitn they're not even compatible with themselves any more. i'm astonished there is a single server left using TNEF.
Jackie Man IT Manager
Top Expert 2010


"It's user error on the sender's part.

Install TNEF's Enough to correct the problem. It's easier to install this app and be done with it than getting Windows users to follow instructions:"


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