crop-swap-mail-list/filters/subscriptions

SUBSCRIBERESP="/opt/cropswap/subunsub.eml"
if ($MAILGROUP ne "")
{
   if (/^Subject:\s*\[(SUBSCRIBE|UNSUBSCRIBE)\]\s*$/)
   {
      SUBSCRIBE=toupper($MATCH1)
      CONTINUE=1
   }
}
if ($DISPATCH)
{
   if ($SUBSCRIBE ne "")
   {
      gdbmopen($SLIST, "C")
      if (gdbmfetch(tolower($FROM)) eq $SUBSCRIBE)
      {
         NOREPLY=$TOPOSTMASTER
      }
      if (gdbmstore(tolower($FROM), $SUBSCRIBE))
      {
         gdbmclose
         EXITCODE=$FATAL
         cc "|$DEBUGMAIL subunsub-fail"
         exit
      }
      gdbmclose
      system "$SUBUNSUB '$SUBSCRIBE' '$ALIAS' '$FROM'"
      if ($NOREPLY)
      {
         exit
      }
      RESP=$SUBSCRIBERESP
      to "|$MAILBOT"
   }
}