As a list owner,  you control the frequency of digests  and when they are
sent.  But  you  cannot  ask  LISTSERV  to resend  an  old  digest  to  a
subscriber, because the digests are erased  after being sent. If the list
is archived, the subscriber can  simply retrieve the information from the
archives. Otherwise LISTSERV just doesn't have a copy any longer.
 
  Eric