How can I make the server syslogs go to someplace other than the mail syslog?
The openlog() call that sets the syslog facility is in src/osdep/unix/env_unix.c in routine server_init(). You need to edit this file to change the syslog facility from LOG_MAIL to the facility you want, then rebuild. You also need to set up your /etc/syslog.conf properly. Refer to the man pages for syslog and syslogd for more information on what the available syslog facilities are and how to configure syslogs. If you still don’t understand what to do, find a UNIX system expert.