Some higher members here might have noticed that I flag quite a bit of spam on a daily base.
By doing so I noticed that almost all of them register and start spamming.
Isn't it possible to block the first posting of a new user until someone actually checked it?
In other forums this is standard procedure and ensures that basically everything the filters miss won't clutter the forum.
It might be a slight delay for those genuine new users seeking help but IMHO it is well worth it....