Here comes the quick and short PS commands to set up an anonymous relay.
New-ReceiveConnector -Name RELAY -usage Custom -Bindings ’10.0.0.1:25′ -fqdn smtprelay.domain.com -RemoteIPRanges 10.0.0.2 -server EXCHANGESERVER -permissiongroups AnonymousUsers
English OS:
Get-ReceiveConnector RELAY | Add-ADPermission -User “NT AUTHORITY\ANONYMOUS LOGON” -ExtendedRights “ms-Exch-SMTP-Accept-Any-Recipient”
German OS:
Get-ReceiveConnector RELAY | Add-ADPermission -User “NT-AUTORITÄT\Anonymous-Anmeldung” -ExtendedRights “ms-Exch-SMTP-Accept-Any-Recipient”
Be sure to edit the bold values to your own environment.
The Bindings’ value you set to the network or server you want to relay.
I recommend to create a DNS entry for this IP, too.
After configuring you have to set your relaying servers’ configuration to this connector.
Cheers,
Chris