This document covers the configuration process for

LMTP daemon installation

The LMTP daemon is available in the package, at the binary lists-srht-lmtp. It needs to run on your mail server, and you need to configure your MTA to forward emails to it. Alternatively, it may be configured to accept SMTP and run on another server. See config.ini for details.

The LMTP daemon uses the same config file as the others, and there are some options there specifically catered to it. The most important is the Unix socket path for the LMTP socket — and the user/group it should be assigned to. Make sure that this is readable and writable by your MTA.

Enable the service and configure your MTA to forward emails to the socket.

Mail Server

The precise configuration of your mail server is a very subjective matter, and we don't have a one-size-fits-all solution to give you. Here are examples of forwarding to with:

local_transport = local:$myhostname
transport_maps = hash:/etc/postfix/transport

# /etc/postfix/transport lmtp:unix:/tmp/
# /etc/smtpd/smtpd.conf

action listssrht lmtp "/tmp/" rcpt-to virtual { "@" = lists }
action "relay" relay

match from any for domain "lists.mydomain.tld" action listssrht
match from any auth for any action "relay"
match from local for any action "relay"

This forwards mail to to the LMTP socket, and processes mail to to local mailboxes. This is just one part of your setup, however, and the remainder of your postfix (or other mail server) configuration is left as an exercise to the reader.

Note: A minimal, local mail server setup which can be used to work on is described in this article.

Celery Worker

On servers which should process forwarding and archival, install the package and enable the service. Make sure you review the config file for worker-specific options as well. The Redis instance you use here should be shared with the LMTP daemon and other worker nodes to ensure that messages can be distributed correctly.

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commit a290ce243e74f89fc35cd4e3467a580edbc35399
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