In message <21773.999569321(a)daedalus.co.nz>, Don Stokes writes:

Mark Foster wrote:

...

Simons Idea of setting up some servers as Secondary MX isnt a silly idea but I need to ask the questions:

Actually, secondary MXs usually are a silly idea, if the MX can't actually do anything useful with the mail apart from queuing it. All they do is take a whole bunch of mail that would otherwise queue at the client end mail server, and put them in one big queue.

Secondary MXes (that can only queue and attempt onward delivery) are about "concentration of pain"; instead of the pain being spread across all the mail servers trying to deliver to the one that is down, it's concentrated in the secondary MX(es). This concentration of pain was more useful in the days when there were quite a few slow, not always up, links trying to deliver mail (especially dial-on-demand type links; uucp tended to be smarthosted once things got to a point that it mattered). Now that the common mode of mail delivery is basically two tier (clients deliver to their ISP's smart host, that smarthost is always connected and "easily" able to retry the mail often enough") there's less advantage in concentrating the pain. Especially weighed against some of the disadvantages you mention (eg, don't get "trouble sending" bounces early if sender end has low timeouts on those, but secondary MX doesn't). Except perhaps when the pain lasts a long time (hours, if not days), and causes a fair amount of trouble to a lot of people/mail servers. Like Xtra at the moment from what I've seen on nznog. BTW, has anyone considered that the reason that no one from Xtra has spoken up is that their outgoing mail is having trouble as well as their incoming mail? :-) Ewen --------- To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog