Discourse provides a demo forum at try.discourse.org. This is useful as a “sandbox” of sorts for tests and experiments in a vanilla Discourse instance dedicated to that purpose.
The forum is (was?) reset daily, which means it is necessary to create a new account to use the site. When I tried to do so today, I discovered that I never received the email required to activate the new account. I see the following message at the top of the page:
Outgoing email has been disabled for non-staff users.
I was able to work around this by creating Discourse ID credentials, but the fact that the site offers signup via email+password credentials when this is not actually supported with the site’s current settings is a poor experience.