YouI want to run a command that lists all mailboxes in a particular Organizational Unit. The OU is called executives, and the parameter is call OrganizationalUnit.

Get-Mailbox -ResultSize Unlimited -OrganizationalUnit "Organization Unit Name"Amit Tank | MVP Exchange Server | MCITP: EMA |MCSA: M | http://ExchangeShare.WordPress.com

The help feature is powershell can answer questions like this quickly. PS C:\> help get-mailbox -examples NAME Get-Mailbox SYNOPSIS Use the Get-Mailbox cmdlet to view mailbox objects and attributes, to populate property pages, or to supply mailbox information to other tasks. Get-Mailbox -ResultSize unlimited Get-Mailbox -OrganizationalUnit Users Get-Mailbox -Anr Chr -DomainController DC01 Sr. Exchange Engineer - Constellation Energy