I had a client that is using exchange 2003 (still waiting for companies to make the jump to 2007/2010) and Rightfax and was trying to have rightfax send messages through exchange using SMTP. Well, the exchange server was blocking the messages, and I told them that they needed to allow SMTP relaying through the exchange environment. Sadly, the tech had no idea how to do this, so I sent him the following:
1. Log into Exchange 2003 server and start Exchange System Manager.
2. Expand the organization name object, and then expand the Servers node. Expand the server name object of the server on which you want to control mail relay, and then expand the Protocols node.
3. Expand the SMTP node, right-click the virtual SMTP server on which you want to control mail relay, and then click Properties
4. Click Relay.
5. In the Relay Restriction dialog box, several options are available. The Only the list below option is enabled by default; the list below this option is empty.
6. Click Add. Enter the IP address of the server that you want to allow relaying. In my example, it would be the ip address of the Rightfax server.
7. In the Relay Restrictions dialog box, click OK.
8. Click Apply, and then click OK in the Default SMTP Virtual Server Properties dialog box.