PROBLEM: When you receive e-mail in Outlook, some of your messages don't download and you get the message: "This item cannot be displayed in the Reading Pane. The item has not been received from the server."
SOLUTION: Tools –> Send/Receive –> Send/Receive Settings –> Define Send/Receive Groups –> All Accounts –> Edit –> Folder Options: Uncheck "Download only headers for items larger than 250 kb
WHY: I assume this is to protect the user from downloading security risks.
NOTE: I use Outlook 2003. I cannot guarantee this is the solution on other versions. However, I am sure it is something similar.