On 10/23/2009 9:42 AM, Curtis wrote:
I run a spam filtering service where the customer points the MX records to our
mail servers and then we forward the filtered mail on to the destination using
the transport table, as follows:
customer.com smtp:[mailserver1.customer.com]
Today I got a request from a potential customer asking if it is possible to
specify a secondary mail server, to be used only if their primary mail server
is down. I don't see a way to do this using the transport table... perhaps
there's another way? Anyone have any ideas for me?
Thanks,
Curtis
Postfix does not support multiple next-hops in the transport
table. That's what MX records are for.
Add local entries to your DNS something like
customer.local MX 10 ip.1
customer.local MX 20 ip.2
and use a transport entry like
customer.com smtp:customer.local
note: no "[ ]" so MX will be used!!
An alternative is to define a new transport in master.cf with
a -o fallback_relay=[some.ip.addr.ess], but that gets messy if
there are more than a few domains needing fallback.
# transport
customer.com customer:[ip.1]
# master.cf
# this is a copy of the "smtp ... smtp" entry
customer ... smtp
-o fallback_relay=[ip.2]
-- Noel Jones
