We have an Application server set up to use our Exchange servers for SMTP Relay. The Exchange server(s) are Windows 2003 R2 64-bit running Exchange 2007 SP1 Rollup 10.
The issue is the Application sends out the emails using the From address format "email@example.com". lgmc.com is our valid domain name. However, we don't have zacepapp.lgmc.com registered as a public sub-domain. We're trying to avoid doing this if possible because we don't really treat this like a sub-domain.
Is it possible to set up a Transport Rule that takes any messages coming from @zacepapp.lgmc.com and redirect them to a valid Exchange account in our environment and then take those messages and deliver them to the original recipient?
The reason we want to do this is because our recipient can't verify the DNS name if we use the sub-domain zacepapp.lgmc.com. If the messages came from firstname.lastname@example.org instead then they could verify the domain.