I have set up each user with alias smtp addresses for different domains in Small Business Server/Exchange. Network Solutions is holding the domain name and I have setup the MX record to point to the correct IP address. DNS resolves to the correct IP address (pinging smtp.XXXXX.com resolves to the correct IP). Exchange appears to be rejecting this new domain name with the following error.
550 5.7.1 Unable to relay for ABC@XXXXX.com 550 5.1.1 <ABC@XXXXX.com>... User unknown
Is there someway to have the users receive emails for two different Internet domains with the same user id?