_mailman not found

I found the local users on the server duplicated with users from the upgrade. 10.4. so I removed those that were duplicated by comparing against a clean system.

I do have the Mailman List Server which has _mailman and mailman but am receiving these errors...

Apr 21 10:23:58 services org.list.mailmanctl[1830]: Traceback (most recent call last):
Apr 21 10:23:58 services org.list.mailmanctl[1830]: File "/usr/share/mailman/bin/mailmanctl", line 735, in <module>
Apr 21 10:23:58 services org.list.mailmanctl[1830]: main()
Apr 21 10:23:58 services org.list.mailmanctl[1830]: File "/usr/share/mailman/bin/mailmanctl", line 349, in main
Apr 21 10:23:58 services org.list.mailmanctl[1830]:
Apr 21 10:23:58 services org.list.mailmanctl[1830]: check_privs()
Apr 21 10:23:58 services org.list.mailmanctl[1830]: File "/usr/share/mailman/bin/mailmanctl", line 288, in check_privs
Apr 21 10:23:58 services org.list.mailmanctl[1830]:
Apr 21 10:23:58 services org.list.mailmanctl[1830]: gid = grp.getgrnam(mm cfg.MAILMANGROUP)[2]
Apr 21 10:23:58 services org.list.mailmanctl[1830]: KeyError
Apr 21 10:23:58 services org.list.mailmanctl[1830]: :
Apr 21 10:23:58 services org.list.mailmanctl[1830]: 'getgrnam(): name not found: _mailman'
Apr 21 10:23:58 services com.apple.launchd[1] (org.list.mailmanctl[1830]): Exited with exit code: 1