Thanks for the reply, just went in and changed it to 'Never'.
Logged in with my newbie account and could still add a signature and access PMs.
Basically I'd like to stop any new members with less than ten posts posting any links whatsoever.
Edit: realised my newbie member was in the "registered users" group. Changed him to "newly registered users" and now no PMs or sig but now he can't view anything and gets the message "This board has no forums".
Edit 2: got it, forum permissions, all forums, newly registered users, and switch them all from "no role assigned" to "newly registered user".