POP3 uses port 110. You can define additional ports if there is a need for additional command-line options for popper. For information on the options that might be suitable for your site, see the z/OS Communications Server: IP User's Guide and Commands.
z/OS® UNIX popper will most likely be used by those whose local mailer requires a POP3 server. Typically their administrator will provide them with the address or name of the z/OS running the POP3 server, with instructions on where this information should be used.
The authentication method used in this implementation of popper is user ID and password.
The popper implementation can be divided into four steps: