Exchange 2007 : Managing Resource Mailboxes
To create a shared mailbox:
New-Mailbox -database “MAILSERVER\MDB1\Mailbox Database” -Name Cancel -OrganizationalUnit “domain.local/Exchange Objects/Resource Mailboxes” -DisplayName “user1” -UserPrincipalName “user1@domain.local” -Shared
To set the country code on the user (may be used for address list policies):
Set-User Cancel -CountryOrRegion “GB”
Grant full access/sendas permissions:
Add-MailboxPermission Cancel -User “user2” -AccessRights FullAccess
Add-ADPermission Cancel -User “user2” -Extendedrights “Send As”