This document will be used to coordinate the effort associated with replacing Mailman 2.

Assorted technical notes:

https://www.sluug.org/pipermail/sysadmin/2023-August/010383.html

Date: Thu, 17 Aug 2023 11:31:08 -0500
From: Ken Johnson
Subject:  Mailman 3

mailman and mailman3 can co-exist under Debian 11. The cli commands are completely different, for example. I did not convert until on Debian 11. There can be python issues, of course – the longer you wait to dump python2, the more that can be messy, though I did not have very many issues personally. In some ways it may be easier to convert after the update, because the version of mailman3 you are moving to is closer to current, so it is easier to find help and information online. Also, for SLUUG the mailing list is pretty exposed to the internet, so best to avoid delay in that conversion, since no updates for mailman will be available.

As you look into this, you will probably see that Xapian is the recommended search option, but it is not the default. Once I got it working, Xapian was fine for me. If I recall correctly,it took me a while to figure out the configuration, because I had a hard time finding examples.

–

First of all, my message of 17 August 2023 contains a critical error. _Xapian_ is the recommended search option, but _Whoosh_ is the default. Replace 'Whoosh' with 'Xapian' in my message of 17 August.

===

This message on the Debian Users mailing list was very helpful to me when I was struggling to configure mailman3.

https://lists.debian.org/debian-user/2022/07/msg00528.html

===

This message thread on the mailman3 mailing list may be helpful:

https://lists.mailman3.org/archives/list/mailman-users@mailman3.org/thread/ZSSVDKKVKZYNQFKLTLWC4V6IIWL7Y3RP/

=== This fragment from /etc/mailman3/mailman-web.py may be helpful as an example:

## 12 Jul 2023 - KLJ - Configure Xapian instead of default Whoosh # # Full-text search engine # HAYSTACK_CONNECTIONS = {

  'default': {
      # You can also use the Xapian engine, it's faster and more accurate,
      # but requires another library.
      # http://django-haystack.readthedocs.io/en/v2.4.1/installing_search_engines.html#xapian
      # Example configuration for Xapian:
      'ENGINE': 'xapian_backend.XapianEngine',
      'PATH': '/var/lib/mailman3/web/fulltext_index',
  },

}

–

Password management: Mailman3 and Postgresql (don't use sqlite for mailman3!) will require the installer to specify some passwords during the setup process. Be prepared, and have a plan in advance for where and how to store and communicate those passwords.