Howard Miller

Moodle can't magically send email. You need to have access to a mail service of some sort and Moodle needs to be configured to work with that.

The server it runs on might (rarely) be able to send mail but that's not going to be the case with Docker containers.

So, if you've done nothing to configure email in Moodle then that's why email isn't working.

It contains all the scheduled and ad-hoc task logs. Yes - you should be able to truncate it with no nasty side effects.

Loads - but Unoconv is useless for anything serious.

Unoconv (bad plan) or Google (or OneDrive) convert from some random document to PDF. However, there's another step to actually display it in Moodle. You also need ghostscript or pdftoppm defined and working in System paths.

As far as I know, there's nothing in the ad-hoc task processing to remove failed emails. So they just keep retrying until they retry every day. This became a significant problem for us because they were crowding out legitimate email.

This seems to me like a bad thing. I run an SQL script to suspend the users (stopping email) and clearing the queue. It's not ideal but is workable.

update mdl_user
set suspended=1
where id in (select distinct userid from mdl_task_adhoc
where component='mod_forum'
and faildelay=86400);

delete from mdl_task_adhoc
where component='mod_forum'
and faildelay=86400;

I plan to code this as a plugin with some extra options/features.