When configuring a SmarterMail server for the first time, there may be cases where you need to open specific ports on either a network firewall or the Windows Server firewall itself. Listed below are common ports that are used for mail delivery:
NOTE: You may need to configure other ports as well if SSL is being configured for use. When specifying those ports though within the SmarterMail interface, you will be prompted to provide a port number at that time. For more information on the process of configuring SSL - see the article: Configure SSL/TLS to Secure SmarterMail. Furthermore, SmarterMail utilizes TCP connections for all ports, with the exception of port 53 (used for DNS only) which uses UDP.