Sometimes you may need to provide few details to the users those who are booking conference rooms, like giving some instructions or providing contact information. To achieve this we used to create an autoreply rule or transport rule in earlier versions of Exchange. But Exchange 2010 Room mailbox has this feature by default.
To enable this:
Open EMCà Room mailboxà PropertiesàResource InformationàCheck “Add additional test” à below type your messageàApply à Ok
Below you can see the difference of default response and custom response.
Default response from Conference room: