bob B via Mailman-users writes:

--Just wanted to check that there is still no way for mailman3 to automatically purge archived emails after a set amount of time?

Pedantically, Mailman itself can't do that, and never will be able to. That's up to the archiver in use. I assume you mean HyperKitty.

it looks like you have to export the database, purge the messages, then re-import, is this still the only/best way to purge old archived messages?

For HyperKitty, this is still true.

This is a pretty hairy operation, and infrequently requested. A bug could be extremely destructive. I expect it will be a while before it is implemented and part of the standard distribution. I guess there may be potential applications where there's something like a max 90 days document retention policy, so there's some room for it. Of course, a volunteer might speed that up. (Money is unlikely to do so, the currently active core developers don't have a lot of time or appetite for consulting.)

--I noticed on the list info page you have metrics, which is straightforward except for "volume" My volume number is not increasing? What is that counting exactly?

Volume number refers to the digest volume. Each digest mail distributed constitutes a numbered "issue". Every once in a while we increment the volume number and reset the issue to 1 so that the issue numbers don't get huge. The options for reset frequency are Daily, Weekly, Quarterly, Monthly, Yearly. If it's one of the longer ones, you're not going to see increments for a long time. And if you have digests disabled, you won't see it increment at all.

--Is there any way to auto discard held messages after x amount of time? I assume not but had a user ask if that was an option.

There currently is no such option. I'm not sure it's a great idea because if x is large, it's not very useful, and if x is small, moderators will go on vacation or get busy at work, and a bunch of valuable messages will be auto-discarded.

If you're not going to be reasonably prompt about moderation, you may as well set the list to discard, not hold. So I'm not inclined to work on this feature myself. I wouldn't oppose another core developer who wanted to add it, and I might even apply a 3rd party patch if it came with a plausible story that I'm at least occasionally wrong about the risk/reward balance I expect.