[Mailman-Users] startup error

[Matthew Kitchin]

Hello,
I have an older redhat box running mailman and sendmail that I am replacing.
I have built a new redhat 9 box with postfix and mailman installed during
the initial OS installation. I can't get mailman to startup properly. It
appears to me running 2.1
running
[root at mail root]# /sbin/service mailman start

Returns this:
Traceback (most recent call last):
  File "/var/mailman/bin/mailmanctl", line 524, in ?
    main()
  File "/var/mailman/bin/mailmanctl", line 319, in main
    check_privs()
  File "/var/mailman/bin/mailmanctl", line 274, in check_privs
    gid = grp.getgrnam(mm_cfg.MAILMAN_GROUP)[2]
KeyError: getgrnam(): name not found

Can anyone tell me how to go about fixing this?

Thanks,
Matthew