You should only open attachments from a trustworthy source
I have dealt with an issue today that took me a little while to figure out.
A user using Outlook 2007 was getting prompted every time they opened an attachment to either save or open it.
"You should only open attachments from a trustworthy source"
On my computer this seemed like a simple fix, unchecked the box that says "Always ask before opening this type of file" However on my end users PC this option was grayed out. Turns out that Outlook needs to be running in Administrator mode. This lead me to my next problem, all their Outlook shortcuts lacked the "Right Click - Run As Administrator" option. So I created a new shortcut for the user on their desktop pointing it to C:\Program Files\Microsoft Office\Office12\Outlook.exe they now have the option to Run Outlook as an administrator.