Outlook 2010 user not able to download images

I have a user that claims he was able to receive email from a certain sender and was able to click download images and everything worked fine.  He said that one day he click something in the download images area and wasn't paying attention and now he can no longer download images from this sender.  The messages up top says "If there are problems with how this message is displayed, click here to view in a web browser"  When I click it view in browser is the only option (the message looks fine in the browser).  The images below are blank but show "The linked image cannot be displayed.  The" and the rest of the message is cut off.  I can not find any settings showing that anything is blocked.  I have tried giving him a new profile and uninstalling and reinstalling office.  I checked for blocked user and added this sender to the safe sender list.   I also tried clearing and moving his temp folder.   All other senders the images work properly.  When I receive images from this sender it works properly.  I feel a setting was changed for his account in Exchange.  We are running Exchange 2007.  Has anyone faced this problem and know how to fix it?