Hi! I have front-end and back-end Exchange 2003. I do not want that my front-end Exchange has SMTP relay functionality. I want to deploy a SMTP relay server in DMZ. My problem is: This SMTP relay server is not a member of my Exchnage AD domain and does not know about mail aliases in my Exchange domain. I do not want that I open additional ports on firewall which is between my Exchange domain and SMTP mail relay. My question is: How can I inform that SMTP relay server knows about all mail aliases on my Exchange domain? Best Regards Mustafa