Why do all my emailed photos arrive as winmail.com on my S7?

[AC Question]

Just got an S7. After setting up my email accounts, I've noticed all the photos that are attached to email now arrive as winmail.com files. How do I fix this?

 

[ManiacJoe]

What email app are you using?
Is it the incoming emails (sent from others to you) that have this problem?
Or, is it the outgoing emails (sent from you to others) that have this problem?

The general description of the problem is that the sender is using the app Outlook (or the server type Exchange) to send emails formatted as RTF, which does "nonstandard" things to attachments like photos. The solution is to update the sender's email settings to that they are formatted at HTML or plain text.