On 05/04/2011 09:36 PM, Christopher Adams wrote:
Hello,
I am attempting to get Postfix working as a relay to an Exchange 2010
server in the same subnet. The incoming mail may originate from the
same subnet, but it all goes through a central server that is outside
the subnet. I am doing this for troubleshooting connections between
the central server and the Exchange server, so it is only temporary.
The outside server would route mail through the server running
Postfix, which would then relay to the Exchange server.
To get the results that I want, without planning for a permanent setup
to relay to Exchange, what Postfix configuration parameters do I need
to set?
These are the parameters that I am guessing have to be tinkered with
and I have added some values, but am unsure about if I need to do
anything with the others. Since I don't want mail to be delivered
locally on the Postfix server, I am assuming that mydestination should
be empty?
When doing this sort of man-in-the-middle magic you need to consider all
worst-case scenarios.
These definitely include exchange being down and your postfix box
queueing the external mail.
Have you considered what should happen in that case ?
relay_domains = $mydestination, ip.of.outside.mailserver
...no, relay_domains contains the domains you wish to relay mail FOR.
In this case, the domains configured on the Exchange server and coming
in via the external MTA.
mydestination = (empty)
You want mydestination set to the resolvable name of this postfix
server, or, at a minimum, to "localhost".
If you set it explicitly to empty then no mail can ever be delivered
locally - including system mail to root or postmaster.
myorigin
Is not directly involved in your setup, and defaults to $myhostname
(which should be fine).
relayhost = [exchange.server.ip]
Note that this will send ALL mail to Exchange, not just the mail you
receive from the external MTA.
Thanks for getting me started in the right direction.
Please start here, and work your way up:
http://www.postfix.org/BASIC_CONFIGURATION_README.html
--
J.
