> > So it looks like Listserv is repeating the attempt to
> >deliver a digest on a regular interval,
>
> LISTSERV(tm) doesn't do this, it is Sendmail that is doing so.  This is
> normal behavior when a transient delivery error occurs (mailbox full is a
> transient error, because it might be cleared up shortly)
 
Yes, sendmail retries.  But it's not normal to receive an error message
for each unsuccessful attempt.  It's hard to tell more about what's
happening without seeing the messages.