On 8/12/2010 9:43 AM, P.A wrote:
Hi, hoping someone can help.
I have a situation that I want to send all outgoing mail to 3
servers that are part of a spam cluster which will check the
email for spam and deliver it.
I was thinking of creating a host in DNS, for example
smtp-relay and have it point to 3 different ip addresses that
correspond to the 3 spam cluster servers.
Yes, this is the proper procedure.
Will this create an
issue if postfix does a dns lookup for smtp-relay and gets an
ip that is down, will it try again,
If one is down, postfix will use the others. If all are down,
postfix will retry delivery for maximal_queue_lifetime
(default 5 days).
or is it best to just use
all 3 servers names in the relayhost option?
No, only one relayhost destination may be specified.
http://www.postfix.org/postconf.5.html#relayhost
Another question is, suppose all three servers are down, can I
have postfix directly deliver the email if all relayhosts are
down, how can I do this?
You can remove the relayhost setting and reload postfix.
Postfix won't do this automatically, but you could use a
monitoring script of some type. Before you do this ask
yourself the question of why use a relayhost at all if you
don't mind delivering the mail directly.
-- Noel Jones
