On Mon, Nov 08, 2010 at 08:43:07PM +0100, Ralf Hildebrandt wrote: > > The fallback relays MUST be loop-free. Thus machine4 must NOT forward > > back to machine1. > > I was assuming that at least one machine CAN send mail :)
Your assumption is unwarranted, and fails to take into account the
possibility of remote failures, that result in mail looping between the
backup machines, while a remote destination is down.
--
Viktor.
