On 2021-06-23 at 17:28:22 UTC-0400 (Wed, 23 Jun 2021 21:28:22 +0000)
White, Daniel E. (GSFC-770.0)[NICS] <daniel.e.wh...@nasa.gov>
is rumored to have said:
Given a pair of postfix instances, one "out front" to be a relay
(MTA), the other "behind" to host mailboxes (MDA)
How do we get the MTA to relay incoming mail to the MDA ? SMTP or
LMTP or …?
Mail sent to the MTA is looking for a "local recipient".
Postfix classifies addresses into 4 classes: local, virtual, relay, and
default. See the ADDRESS_CLASS_README in the distribution or at
http://www.postfix.org/ADDRESS_CLASS_README.html for details. The short
version is that you need to tell Postfix what domains you want to relay
mail for and where to send it. The simplest way to define that set is
with the relay_domains configuration parameter, documented in the
postconf(5) man page.
Then the same question for outgoing mail from MDA to MTA to final
destination.
To have a Postfix instance send all 'outbound' mail to another machine,
you need to define the 'relayhost' parameter. The postconf(5) man page
describes that and all of the other available configuration parameters.
Note that you will also need to have the inside machine understand what
addresses it to to treat as 'local' (real system accounts) and 'virtual'
(addresses that deliver locally but do not map directly to a system
account.)
Our dilemma is that most online tutorials and how-to's have everything
on one server.
Postfix's own documentation is very helpful, and is much more reliable
than what you might find on a random web page. The README files in the
distribution hint at their purpose in their name. The
STANDARD_CONFIGURATION_README is particularly useful and describes
something close to what you are setting up.
--
Bill Cole
b...@scconsult.com or billc...@apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Not Currently Available For Hire
