Quoting Michael Paoli (Michael.Paoli@cal.berkeley.edu):
And ... well, not exactly step-by-step, but tracking fair bit of migration and testing here: https://www.wiki.balug.org/wiki/doku.php?id=balug:mail_and_lists
Includes:
mailman admin commands should work via email (need more complete list)
This is woefully underdocumented (and underdeveloped?). I'm really not the extent of such functions. The standard doc for Mailman listadmins doesn't mention any, but it's known to be incomplete: https://www.gnu.org/software/mailman/mailman-admin/index.html Here's an example, showing how the listadmin can approve/reject/discard a held message entirely via e-mail: https://wiki.list.org/DOC/How%20do%20I%20respond%20to%20a%20held%20message%2...
That is in response to a held-message notice. In general, it _appears_ that Mailman doesn't really offer to listadmins the abilities it does to them via the WebUI.
In the Mailman conceptual model, docs are kept separately for users, listadmins, and site admins.
Maybe one reason for paucity of administrative functions via e-mail is that the command-line tools for site admins are so excellent -- from the Unix shell. Here is the list of the standard tools:
https://www.gnu.org/software/mailman/site.html
During the years that Marc Merlin administered the SVLUG mailing lists, he made me aware that there is also a robust and active community of people making additional command-line tools for Mailman that are not necessarily included in the Mailman standard package. I have a bunch of those that Merlin collected on linuxmafia.com in an archival replica of what Merlin put together.