I use Microsoft Outlook, but a lot of folks I send emails to do not. I get complaints from some of my friends (especially those that read my emails on their iPhones) that rather than message content, all they got was an attachment named winmail.dat. They can’t open the attachment, so they can’t read the email I sent. It’s awfully frustrating for everyone involved. Can you let me know how to fix this problem?
So let's see. We're currently on Office 2016 which is like the umpteenth a version of Microsoft Office and certainly the fifth or sixth version of Microsoft Outlook and you would think that by now Microsoft would have fixed this problem which has been a constant problem for a number of years.
The problem is Outlook is formatting its data when it sends out an email using a format called RTF or Rich Text Format. People using iPhones don't have support for this particular format. So all they get is a little attachment and they can't open it. I work around it by opening the mail in the GMail app instead of the built in Mail app but that's kind of a pain. The answer is pretty simple though. The answer is never communicate with those people ever again. I'm sorry that's not really the answer. The answer would be in Outlook, go to the settings and tell Outlook to send mail not in RTF format but in HTML format. HTML as another formatting Protocol. So that people can communicate with each other and it's one that's supported by pretty much every device. Not every device supports RTF but every device supports HTML. It's up to you but that will certainly make your friends happier with the emails you send.