In your Exchange environment, it may be necessary to allow a device to relay to outside recipients off of the Exchange server. Allowing this change is simple through the use of Powershell.
To allow relaying to outside domains, do the following:
Open the Exchange Management Shell
Issue the command:
Get-ReceiveConnector “CONNECTORNAME” | Add-ADPermission -User “NT AUTHORITYANONYMOUS LOGON” -ExtendedRights “ms-Exch-SMTP-Accept-Any-Recipient”
Be sure to replace CONNECTORNAME with the name of the receive connector that will be handling the request. If you are unsure of the name of the receive connector, issue the following command:
The Exchange Management Shell will display the receive connectors that exist on this Exchange Server.