I have another server in the enterprise that has the simple IIS SMTP server installed on it (Server 2008 r2), and it can accept e-mails that I write by hand over telnet to port 25, so I know that it's working. Now I need our Exchange (2003) server to be able to send mails to it. I tried adding a contact in active directory with scc-scsm@scc-scsm (the name of the server with SMTP on it) as the SMTP address, but mails to it bounce back with:
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<mailserver #5.7.1 smtp;550 5.7.1 Unable to relay for scc-scsm@scc-scsm>
The purpose of this is to allow people to submit helpdesk tickets via e-mail to this server (SMTP on the server just drops them in the drop folder as .eml files and the helpdesk software picks them up).
What do I need to change in Exchange to make it able to relay messages to this other SMTP server?