When you create a new resource mailbox by using Exchange Admin Center (EAC) in a Microsoft Exchange Server 2013 environment, the resource mailbox is not stamped with the SMTP address from the email address policy. Additionally, the Automatically update email addresses based on the email address policy applied to this recipient option is not select in the properties.
NoteThe Automatically update email addresses based on the email address policy applied to this recipient check box is selected to have the recipient's email addresses automatically updated based on changes made to email address policies in your organization. This box is selected by default.
This issue occurs because EAC calls the New-Mailbox Windows PowerShell cmdlet and specifies the PrimarySMTPAddress parameter. When the New-Mailbox cmdlet is passed the PrimarySMTPAddress parameter, the Automatically update email addresses based on the email address policy applied to this recipient option is not selected. This is to prevent the email address policy from changing the primary SMTP address that was specified in the command.
To resolve this issue, install the following service pack:
2926248 Description of Exchange Server 2013 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about how to create and manage room mailboxes, go to the following Microsoft website: