I'm running Windows and want to know if I can run a POP/IMAP mail server on the same machine as LISTSERV.

LISTSERV's SMTPL.EXE "listener", which passes inbound mail to LISTSERV in a format LISTSERV can understand, requires exclusive access to the SMTP port for incoming mail by default. However, it is possible to run the "listener" service on a non-standard "high" port such as 40025 and use another mail server to accept inbound mail on port 25 and forward the mail intended for LISTSERV to the "listener" service on the non-standard port.  L-Soft's support staff will be happy to provide more information regarding the nuts and bolts of how this can be done.

Please note that this restriction does not prevent you from running a Web server or other Internet service on the LISTSERV machine. Only mail services use the SMTP port, so there is no conflict.