Hi, I am having a problem with receiving emails from external mail servers. I have a single exchange server. I am not receiving any emails from external mail servers. I do have an MX record with my provider. What is the receive connection authentication security mechanism I should be using if emails will be coming directly to my exhange server? Also, what permission groups should I use? thanks, Anatoli

the simple solution is: You should have a MX record in external DNS pointing to A record and then to aIP on your Firewall, On your firewall make portfordarding rule for that IP and port 25 to your Exchange servers internal IP. on the Receiveconnector, permission groups tab, enable anonymous users, on the authentication tab leave it with default settings. then you must tell Exchange wich domains it should accept mail to, this is done on organisation configuration/hub/accepted domains tab