How To Allow Relaying in Exchange 2010 and Exchange 2007
Starting with Exchange Server 2007, Exchange implemented its own SMTP protocol stack – unlike Exchange Server , you no longer need to install the SMTP service from IIS . SMTP Virtual Servers have been replaced by Receive Connectors . Understandably, the way you allow relaying has changed as well.
Do you really need to allow relaying?
Before you setup anonymous relaying, it’s important to understand the need for relaying. If your application servers or devices like copiers need to send mail only to internal recipients – i.e. mail to addresses for which Exchange has an Accepted Domain (or a Recipient Policy in Exchange Server ) and therefore will receive inbound mail for, it is not considered relaying . The application server or device should be able to do this without any configuration on Exchange.
Recipient Policies and Exchange Server
In Exchange 2003, Recipient Policies tell Exchange which domains to receive inbound email for, and to generate email addresses for recipients using those domains. Exchange 2007 splits this functionality into two parts: