Support Forum

Let's answer back to front. The moderation system allowing people to freely post after a single post has been approved is straight out of the WordPress protocol for comments (see WP admin > Settings > Discussion - Comment author must have a previously approved comment. This amounts to the same thing as we have with the forum). We could certainly consider making it an option at some point in the future but I believe this is the first request for such an addition. Still - it is noted.

As to blocking an email address - or indeed blocking any other identifying characteristic - from registering an account then that really is beyond the remit of the forum. This is pure WordPress territory which is solely responsible for user registrations, logins etc. I would suggest you take a look at some of the excellent membership plugins that are available in the WP plugin repository.

If a user does manage to register whom you wish to deny form access to then you can easily do this by placing them in a user group with no permissions. Or we do have a couple of forum plugins for banning users (our basic 'ban' plugin and the 'warn, suspend and ban' plugins).