Unable to open archive items in Enterprise Vault Integrated Search

Does the message get prompted to save as a MSG file? or does it immediately attempt to open in Outlook?

But OK, so since EV8 I believe, the EV Client was not installed as part of the server build, meaning the EV tools shouldn't show in Outlook. But you're saying the toolbar shows in Outlook and you can click integrated search? which means on that server you have the client.

And if you haven't been updating the client when you install the server, could be that you have a really old client version when running 10 SP1. And even then having the client installed on the server is a really bad idea.

But can you check through Programs and Features that the Symantec Enterprise Vault Outlook Add In is or is not installed? If the client is installed and you uninstall it, you'll probably break the server because it shares the same registry keys and will remove keys that the server is dependant on.

Really though, you should stop the EV Services, uninstall the client, reinstall the EV Binaries and reboot the server. You will lose the EV toolbar in outlook, but you should be able to retrieve items from AE/Search etc