Whilst doing some work hardening the server’s firewall, I inadvertently caused a firewall issue which prevented the forum from sending (and possibly receiving) e-mail, such as notifications, password resets, etc, for about the last 20 hours.
The docker container that runs the Discourse app couldn’t make certain outbound connections.
This has been resolved.
Unfortunately I don’t think there was any ‘backlog’ or queue of pending emails, they simply failed to send. Actually, looks like delayed mail is starting to send after all.
Sorry about the disruption; for context, we’re going through a bit of a busy period of making lots of improvements to the server, and, in what is a classic for a security-focused project, sometimes we make things a little ‘too’ secure