I need to install Exchange 2010 for a client and want to install it on a single server. I've previously done two migration upgrades from Exchange 2003 but this install has no prior Exchange servers. I tried installing 2010 and peformed the basic configuration steps, setup send and receive connectors and tested. I can send email to outside email accounts and between Exchange accounts internally but I cannot receive test emails from outside. I've got anonymous users checked in my receive connector configuration. I've tested using telnet from another system internally and successfully sent an email from an outside email account. I cannot telnet in to port 25 from outside my network. My firewall is configured to accept port 25 traffic inbound and I have a DNAT from the WAN IP address to the Exchange server's inside LAN IP for all port 25 traffic. This server has the CA,HT,MB roles installed. Do I require the Edge Transport role added and can I have this one server host all the roles?