LMTPSympa

LMTPSympa is an LMTP/SMTP frontend for Sympa mailing list management software (MLM).

Install

1. Install Go. Go v1.18.x or later is required.

2. Build LMTPSympa. Run:

   $ go install github.com/ikedas/lmtpsympa@latest

   and put the executable file lmtpsympa into anywhere you prefer.

3. Create the configuration file lmtpsympa.yml. See also lmtpsympa.yml.sample in the repository.

To launch LMTPSympa, you may run either

lmtpsympa lmtpsympa.yml

or

lmtpsympa < lmtpsympa.yml

LMTPSympa safely terminates on receipt of TERM or INT signal.

Deploy

The following is an example of deployment with Systemd/Launchd and Postfix.

1. Configure LMTPSympa

Create lmtpsympa.yml:

%YAML 1.1
---
domain: mail.example.org
# Add the other virtual domains to "domains" if any
home: /var/lib/sympa/list_data
queue: /var/spool/sympa/msg
queuebounce: /var/spool/sympa/bounce
service:
  addr: :8024
  #addr: 127.0.0.1:8024                     # IPv4 loopback
  #addr: [::1]:8024                         # IPv6 loopback
  #addr: /var/run/sympa/lmtpsympa.socket    # UNIX domain socket
  mode: 660

2. Register the service

With Launchd

Create /Library/LaunchDaemons/community.sympa.lmtpsympa.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN"
"http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>community.sympa.lmtpsympa</string>
    <key>UserName</key>
    <string>sympa</string>
    <key>GroupName</key>
    <string>postfix</string>
    <key>Program</key>
    <string>/usr/local/bin/lmtpsympa</string>
    <key>StandardInPath</key>
    <string>/usr/local/etc/lmtpsympa.yml</string>
    <key>KeepAlive</key>
    <true/>
    <key>RunAtLoad</key>
    <true/>
    <key>Umask</key>
    <string>027</string>
    <key>StandardErrorPath</key>
    <string>/var/log/lmtpsympa.log</string>
</dict>
</plist>

Note that, On macOS, this file has to be owned by root:wheel and writable by root; GroupName may have to be _postfix.

Then you may run

$ sudo launchctl load -Fw /Library/LaunchDaemons/community.sympa.lmtpsympa.plist

to start the service immediately.

With Systemd

Create lmtpsympa.service:

[Unit]
Description=LMTPSympa - LMTP/SMTP frontend for Sympa
After=syslog.target network.target

[Service]
Type=simple
ExecStart=/usr/local/bin/lmtpsympa /usr/local/etc/lmtpsympa.yml
User=sympa
Group=postfix
KillMode=process
Restart=always

[Install]
WantedBy=multi-user.target

put it into appropriate place, /etc/systemd/system, /usr/lib/systemd/system or somewhere, and run systemctl daemon-reload.

Then you may run

# systemctl start lmtpsympa.service

to start the service immediately.

Confirm the operation

• If you configured LMTPSympa to use UNIX domain socket, make sure that the socket path is created and its permission allows Postfix to access to.

  $ ls -l /var/run/sympa/lmtpsympa.socket
  srw-rw---- 1 sympa postfix 0 Mar 12 09:44 /var/run/sympa/lmtpsympa.socket

• If you configured to use TCP socket, make sure that appropriate port is listened.

3. Integrate to the MTA

Edit main.cf and the other configuration files of Postfix:

• The existing configuration for Sympa should be disabled.

• Add the domain(s) dedicated for mailing list service to the transport(5) table, for example:

  mail.example.org lmtp:inet:127.0.0.1:8024
  ...
  

  mail.example.org lmtp:inet:[::1]:8024
  ...
  

  mail.example.org lmtp:unix:/var/run/sympa/lmtpsympa.socket
  ...
  

• Create /etc/postfix/lmtpsympa_domains:

  mail.example.org reject_unverified_recipient
  ...
  

  Don't forget to run postmap /etc/postfix/lmtpsympa_domains.

• Add the domain(s) dedicated for mailing list service to relay_domains, and enable recipient varification for them, for example:

  relay_domains = $mydestination, hash:/etc/postfix/lmtpsympa_domains
  smtpd_recipient_restrictions = (existing settings...),
    check_recipient_access hash:/etc/postfix/lmtpsympa_domains
  unverified_recipient_reject_code = 550
  

  Note that the default value of relay_domains is the value of mydestination. It should therefore normally be included.

4. Modification on Sympa

• If all deliveries to mailing list service are made by LMTPSympa, you may disable update of mail aliases. In sympa.conf and/or robot.conf, set:

  aliases_program none
  

• For the same reason, setuid programs queue and bouncequeue should also be no longer needed.

---

License

This software is licensed under the terms of MIT License. See LICENSE file for more information.