I found this:

https://legacy.itic.ioc-unesco.org/legacy.itic.ioc-unesco.or...

The article contains a link to subscribe to a list, which is a web form, hosted at exactly the same list server domain:

https://lists.unesco.org/subscription/?action=subscribe&list...

I put in a fake address there; it told me it sent a subscription e-mail to that address. Whether it did that, I have no idea.

What is supposed to be at the above non-working page? I'm guessing access to searchable mailing list archives? Hmm. You don't strictly need those to get a bulletin.

Anyway, the above article says, at the bottom:

UNESCO does not warrant, guarantee, or make any representations regarding the timeliness, currency, correctness, accuracy, reliability, or other aspect of the characteristics or use of the information available through this email service.

So, yeah, what I said ...