How to configure an internal relay connector in Exchange 2013
Go to the webpage of the exchange management page (https://exchangeserver/ecp)
Go to the Mail flow > Receive Connectors > + for add a new connector.
Select role (Hub Transport) and type (Custom) click on Next
Additional note. If you want to relay outside your organization than you need to select Frontend Transport role instead of the Hub Transport role. (Information from the command’s below)
Click on Save..
now you have to open a powershell CLI of exchange on the exchange server ( with administrative rights )
Get-ReceiveConnector “Receive Connector Name” | Add-ADPermission -User “NT AUTHORITY\ANONYMOUS LOGON” -ExtendedRights “Ms-Exch-SMTP-Accept-Any-Recipient”
(Now you should be able to send a email message form another server or application located on another server)
To test your settings from an other server you can use QuickMail: http://www.freddejonge.nl/files/QuickMail.zip