I have an emergent need with exchange 2010 acting as an open relay. I have checked all the settings through the EMC and they look good. I have issued the following command on all the receive connectors and it either remove the access or said there was no ACL. Get-ReceiveConnector “Windows SBS Internet Receive SMSCORPVS0SBS” | Remove-ADPermission -User “NT AUTHORITY\ANONYMOUS LOGON” -ExtendedRights “ms-Exch-SMTP-Accept-Any-Recipient” . It is still showing it as open. Any help please!