We just added a new certificate to our Exchange 2007 box (to get our smartphones to receive email) and since this has been installed, all of our users now get a security warning message every time they open Outlook.
I have googled this issue and read through Microsoft's support pages regarding this, but I have yet to find a Microsoft support page that has ever been helpful with any issue I have had, and this record still stands! ;)
Has anyone come across this before, or knows how to fix it? It's very annoying.
Note: A rebuild of the user profile client-side doesn't remedy the situation at all, it seems to be a server-side problem.
Users are using XP and Windows 2007, the problem is identical on all machines.