Thanks for the inquiry. Can you please confirm if you have the IP bindings to the ports enabled for the localhost [127.0.0.1] in the settings ? Log in as the System Administrator. Click on Settings | Bindings | IP addresses. Choose the 127.0.0.1 IP and enable the ports, specifically port 25. You then should be able to telnet to the port at a command prompt.
Please make certain that you do the same for any other IP that you may have assigned to the Domains on the server.
Please let us know if you need further assistance by opening a Support Ticket for us to troubleshoot this issue.