Getting the total count on the mailbox is very easy using Exchange Management Shell Commands and below are few useful examples How to get the Mailbox Count in a Database (Get-Mailbox -ResultSize Unlimited -Database "Database Name").count How to get the Mailbox count in a Server (Get-Mailbox -ResultSize Unlimited -Server "Server Name").count How to get the Mailbox Count from the whole organization (Get-Mailbox -ResultSize Unlimited ).count Ok, I got the total count, now are you searching for option on how to get the room mailbox count? (Get-Mailbox -ResultSize Unlimited -filter (RecipientTypeDetails -Eq "RoomMailbox")).count How to calculate the Mailbox count which includes the disabled mailboxes in the database (Get-MailboxStatistics -Database "Database Name").count Hope its useful for you. Leave your comments if any details required.