Right now, if you enable the client side auto archiving in Outlook, and have multiple accounts configured in Outlook, all messages from all accounts are archived into the same .pst file. This should not be the case.
Why not make actual "automatic" out of office replies based on user connectivity and automatically forward to any of the following:
> The distribution group the user belongs to (Small groups)
> User Selected member(s) of his/er distribution group (Larger Groups)
> User Selected member(s) (Non grouped users)
> Administrator Selected member(s) (Non grouped users)