SUGGESTION:

Hide the "Private Messages" link in the main navigation menu for users who are unable to use the PM system (e.g. new members with too few posts) AND put a warning on the Private Messages dashboard (https://forums.onlinebookclub.org/ucp.php?i=pm&folder=inbox) that the PM system is for messaging other members of the website, not for contacting our Customer Support. In the warning, include a link to the actual contact form.

REASON:

New users who click the navigation menu see the "Private Messages" link and falsely assume means "Contact Website Support Team Privately" and then get frustrated and confused when it doesn't work.