Oops, now I see that the original post says that new members cannot even send a message, which is not the case.
I did send 1 message as a new member.
So apparently new members can send 1 message at a time. It is not clear if they can receive.
When I was on the staff, it was at 10 posts that some of the spammer protections became lighter. You might try posting four more times (as your current post count = 6) and see if that helps.