There is an issue with the current email provider, and the forum can’t send emails until it is resolved.
So, you won’t receive notifications and new users can’t register.
Hopefully, this will be quickly resolved.
For those who like technical details: a lot of users still have non-working @unicyclist email addresses, and the email provider didn’t like it (too many email bounces) and disabled the email sending until I fix the issue.
edit: I did some configuration in order to fix the issue, and I’m waiting for the email provider to re-enable the email sending. It should take 24h at most.