I don't think the site attracts more spam than any others, it's just not getting filtered out properly. It's a cat-and-mouse game but are methods to do that. We don't know what's in place now but it clearly needs looking at. Only Rob has that capability as it's down the the Xenforo software config and add-ons. Upgrading it to a version that's actually supported would be a good start.
If you sent it just to Rob then you could be waiting indefinitely. I've sent one or two PMs in the past and never got a reply. Make sure you tag @Havit or send him a PM. He is around but whether he can help...
Page 1620 of the “This made me laugh” thread has just one post on it. It is not the last page. And the next one only has 3. What on earth is going on with this forum engine.