Change the chat and mail system to only allow 1 space in between words or letters.
Now create a list of every known gold seller site, with every possible “spelling” for that site.
And now if any thing on that list comes up, it is automatically blocked from being sent in chat or in mail.
This is better than nothing, which is what seems to be happening. I have map chat off cause I don’t want to see gold ads, and reporting the mail does nothing.