Yep. This should now be fixed.
The email account got a security lock for spam concern.
Ironically, it looks like this happened because the forum was subjected an unusual spike in spammer load about a month ago. If you look at the bottom of the forum index you'll see that "Most Online Ever" got bumped for the first time in like 6 years, and that was probably from spammers. I just purged a spam account queue of more than 12,000 attempted registrations.
Luckily the spam blocking has mostly been working so it didn't really affect anything. But sending thousands of "Your account is registered, but needs admin approval" emails in such a short time seems to have triggered an anti-spam check from the email provider.