I have received a .msg file as an attachment from a coworker. I am using OS X and there are no default programs to open the file. Does anyone know how I can open a .msg file on my Mac?
I believe Outlook for Mac should be able to read them, but if you don't want to buy that or generally don't want to install Microsoft programs on your Mac, MailRaider is a free program that should be able to read those files just fine.
It should be able to read the files and even save attachments. You can find the documentation here (PDF).
Here's a caveat about files that don't originate from Outlook: