Outlook 2010 - .msg file error " Cannot read the item"

We are running Outlook 2010 and Office 365.

I have a user that saves important emails to his network drive as a .msg files.  Most of the files he can open but there are a few that he cannot.  He receives the message  "Cannot read the item" when he tries to open them. 

When I go to the network drive and try to open the .msg file I get the same message.  I had him email the message to me as an attachment.  When I try to open the attachment from inside the message I get error "you don't' have appropriate permission to perform this operation".  When I save the attachment to my computer I receive the "Cannot read the item" error again.

Any ideas would be appreciated.