com.apple.launchd[1] (0x10f860.cron[43786]): Could not setup Mach task special port 9: (os/kern) no access

If you’re seeing this warning/error in your OSX Server log files, it is more than likely caused by cron running jobs for mailman subsystem. Even if the Mail process is disabled in Server Admin, OSX will try to run these cron jobs. The way around this (only do this if you’re NOT running mail server or mailman mailing list manager on your box) is to comment out all lines in /usr/lib/cron/tabs/_mailman file (insert a # character at the beginning of each line that doesn’t have it). This fixed the problem for me…..hopefully it will also work for you :-).