This is because you have installed other applications that relate to the mail service on your server - this creates a conflict on the device. To be more specific:
1) In the case where you installed an anti e-mail virus program, then a port 110(POP3) conflict may occur. You will need to change the port for the anti-virus software. However, not all anti-virus software supports port revision. If you can't change the port, then you will have to stop the anti-virus function. Although CCProxy provides a function to change the POP3 port, we don't suggest you to do so. Norton doesn't cause any problems and CCProxy works well with Norton.
2) In the case where you installed other proxy server software, then a conflict of port 110(POP3) and port 25(SMTP) may occur. This is because some proxy servers simultaneously have a mail proxy function. You will need to stop the mail proxy function of those proxy servers.
3) In the case where there is an installed firewall application, a port conflict might occur. You will need to open the following ports: 25(SMTP), 110(POP3), 53(DNS), 80(HTTP), 8011(Admin) and 5353(MX).
4) In the case where there is an installed mail server application, if it is using the same port as that of proxy server, then a port conflict will occur. Stopping those mail servers will make CCProxy perform normally.
5) If you are sure other applications can assume the mail proxy function (e.g. CMailServer), then go to CCProxy "settings" and uncheck "Mail proxy".

A simple way to check which program is related to a mail service is to run the command "telnet 127.0.0.1 110" or "telnet 127.0.0.1 25" on a command line. It will tell you which program is related to this port.