If you encounter a problem where an Exchange Server 2007 room mailbox is not automatically accepting meeting bookings, here are two quick steps to follow.
First, double-check that the room mailbox is configured correctly for auto-acceptance of meetings. The correct setting is “AutoAccept”.
Get-MailboxCalendarSettings homeetingroom1 Identity AutomateProcessing -------- ------------------ exchangeserverpro.net/Company/Head Office/Users/HO Meetin... AutoAccept
If it not set correctly you can use Set-MailboxCalendarSettings to correct it.
Set-MailboxCalendarSettings homeetingroom1 -AutomateProcessing AutoAccept
Note if you need to do this for multiple room mailboxes at once try this tip.
If meeting requests are still being received by the room mailbox and sitting in a tentative state, with no confirmation message back to the meeting organizer, make sure that the Microsoft Exchange Mailbox Assistants service is running on the Mailbox server.