Q. "How many PM's do new members have"
A. Users can only send X number of posts per day where X is the same number as their post count. That means that if a user has only posted to the forum once, they can only send 1 PM per day. The rationale is to cut down on the ability for users to spam via the PM system as they must be active participants on the site before they can even attempt to abuse the system. Users are also required to post once in the forums before they can PM at all to ensure that moderators can see the user interact in a public place before they are allowed to communicate privately.