I just looked and there were over 4000 files in the /var/spool/listserv
directory (we run 1.8c on Solaris).  Most of these files are dated
*a long* time ago (several months).  My question is:  how much, if any,
of this can I delete?

A couple of the sample filenames are (from a ls -al)
  1161 Oct 23  1996 10072.error
  1247 Oct 15 17:05 3154034_0_10_x-supd_job.error
  1174 Jul 31 13:55 2038400_8_gun
  4375 Sep 12 13:41 2521642_8_"listname".jobh
   755 Nov  4 12:52 3794010_0_9_x-del_job.error
     0 Nov 19 15:15 in347356ed-000ab