relaying redundancy

[jwelsh]

I have a qmail server set up such that it's being used as a relay (all incoming
mail just gets dumped to whatever is in smtproutes). anyway, sometimes the
machine that my qmail box is relaying to goes down or crashes, whatever. Is
there a hack to allow qmail to relay somewhere else if that host is down or if
the queue builds up to a certain number (which usually also means that the host
its trying to relay to is down)?

regards,
Jason