This helps.
All the outgoing mail is to go through an upstream relay cluster, so I can set
"relayhost" to that.
Incoming mail - for a single, local domain - goes to an MDA server that has
Dovecot and Roundcube in addition to Postfix. It sounds like I can use
"relay_domains" and/or "relay_transport" to direct the message to the MDA
server.
Then, it occurs to me that I can maybe use "relay_transport" for both, like
this:
.our.local.domain smtp:[ MDA server ]
* smtp:[ upstream relay cluster ]
Does this sound proper or should I get my medications adjusted ?
-----Original Message-----
From: Wietse Venema <wie...@porcupine.org>
Date: Thursday, August 5, 2021 at 10:40
To: Daniel White <daniel.e.wh...@nasa.gov>
Cc: "postfix-users@postfix.org" <postfix-users@postfix.org>
Subject: [EXTERNAL] Re: Inbound/Outbound Settings on a Postfix Relay-Only
White, Daniel E. (GSFC-770.0)[NICS]:
> I am somewhat confused about which parameters apply to an outgoing vs an
incoming message.
>
> I think that
>
> relay_transport mail that you're willing to forward
> relay_domains and mail that you're willing to forward
> relayhost mail that you're delivering remotely
>
> apply to outgoing messages.
relayhost and default_transport are for deliveries to all other
domains.
relay_domains and relay_transport are for remote destinations that
list your system as primary or backup MX host.
> I think that
>
> virtual_transport and
> local_transport (set to " error: local delivery disabled")
These are typically used for local deliveries.
More in http://www.postfix.org/ADDRESS_CLASS_README.html
Wietse
