Some administrivia below: On Mon, Dec 19, 2022 at 05:32:30AM -0500, Karl Semich wrote:
Greg, thank you for addressing publicly the concern Rooty raised.
It's truly my pleasure :)
I hope this helps! The server we use seems to be reliable overall, and should not be taxed due to high list traffic, subscribe/unsubscribe, spam, etc.
Given this has not always been the case in the past, has the server been upgraded in the past year or two? Or how long should messages take at low points?
Nothing has changed - messages should be processed in at most a few minutes. Once the Mailman software begins sending messages to list subscribers, it can take a few minutes for everyone's message to arrive because it does this in small batches. I estimate that full delivery should always take under 20 minutes. If someone's mail system is not available, then it's up to Postfix to attempt redelivery. This follows a pattern of retrying after 5 minutes, 30 minutes, an hour, 3 hours, 6 hours, then daily for (IIRC) 7 days -- or something like that. Basically, it retries quickly the first few times, then retries slowly. Mailman counts any bounces from a subscriber, including for temporary issues for things like being over quota. After a week's worth of bounces, addresses are automatically removed from the list. You get a notification if this happens to you (also a warning!), but of course if your email isn't accepting incoming messages from the list, you won't get the warning either. All of the above is completely standard for Mailman (the mailing list software) and Postfix (the mail transport agent). This is all running on an Ubuntu 18 server with a dedicated 1Gb uplink. I'll be upgrading it to Ubuntu 22. ~ Greg