FYI, I recently upgraded the forum to the latest version (minor bugfixes mostly) and it seems something broke the functionality that sends email. To avoid overloading things, email sent by the forum gets queued up and sent gradually (on this forum usually within a few minutes of the time it's queued up). For some reason the functionality to send the mail isn't sending it, so you won't get email notifications at the moment. It's been reported to the developers and hopefully should be fixed soon. I will look into it myself when I have time as well.

Update: A fix has been applied and email appears to be working now. I'll keep an eye on things and make sure.