Netwide delete is no longer supported.  See the following from the
release notes for version 1.8a.
 
 8. As  announced in the 1.7f  release notes, support for  netwide DELETE
    jobs has  been removed  (netwide SIGNOFF  is still  supported). Sites
    running LMail, MX  V3.3 or PMDF V4.2 need not  worry about submitting
    netwide DELETE jobs  for expired accounts as their  mail system takes
    care of  that automatically.  Sites running older  versions of  MX or
    PMDF should upgrade to the current version. The specifications of the
    LMail/LISTSERV  delivery  error  format  are  available  from  L-Soft
    support.
 
    ************************************************
    * Warning: do NOT use netwide SIGNOFF instead! *
    ************************************************
 
    Support for  netwide DELETE has  been removed because this  method of
    broadcasting  information  about  the  deletion  of  hundreds  of  of
    thousands of local accounts every semester to the entire network does
    not scale up and placed an unbearable load on the hosts providing the
    LISTSERV service.  Do not modify your  procedures to use a  series of
    netwide SIGNOFF jobs  instead, as the overhead would  be even higher.
    Netwide SIGNOFF remains  for the convenience of  individual users who
    know for  a fact that they  are subscribed to mailing  lists, and for
    emergencies.  If  the  LISTSERV  backbone is  flooded  with  tens  of
    thousands of  "preventive" netwide SIGNOFF  jobs from users  who have
    never been  subscribed to any  list, the  overhead will be  such that
    there  will  be   no  alternative  but  to   remove  netwide  SIGNOFF
    permanently.
 
 9. As a corollary to the removal of netwide DELETE and the conversion of
    the DELETE command  to PASCAL, support for the "DD="  syntax has been
    removed. This syntax  was needed only to support netwide  DELETE in a
    more efficient manner.  Simply issue multiple DELETE  commands if you
    need to  remove multiple users from  a list. The setup  overhead with
    PASCAL command is  much lower and there is  no noticeable performance
    impact unless hundreds of users are to be removed.
 
 --Nathan