We are trying to configure Exchange 2007. We are able to send/receive internally and send emails to external email addresses, however are unable to receive emails from external email accounts. We have checked the firewall, port 25 is open. We are able to successfully telnet to port 25 locally but not externally. We have even bypassed the network altogether (server directly to cable modem) but still cannot telnet to port 25. I believe the issue is this, however we cannot figure out why telnet is unable to connect to SMTP. We have set anonymous access in the hub transport settings... so we cannot figure out what is going on. Anyone have any ideas? Desperate to get this going!