Due to malfunction of email delivery, user registration has been disabled temporarily.

A support ticket is pending with the host. I will add updates here.

Still waiting on the host response.

In the meantime, it looks like the DNS records for the host's email servers are missing. I will have to dig into all of my DNS settings and start updating those in the meantime.

Email delivery is working again. After reconfiguring the MX records and setting up a new SMTP account, it appears the host is only accepting mail via SMTP this weekend.

There was no advance notice and no meaningful response from the host. I'm hoping this was just a one-time incident.

User registration is enabled now.