Moderation of blogs from new users

This feature might actually already exist somehow, but I'm looking to moderate the first number of posts made by registered users. On a consistent basis, spammers create a new account on the site and post a blog. I have a solution you all created where it does not send out an email to subscribers, but that still means the post is up on the site and distributed through social channels. Instead, I think we just need to moderate the first number of posts. Is this possible, and if not, can it be done? I'm willing to pay for this feature if needed, as it makes the site look really unprofessional.

Thanks!