I am sorry we cannot re-enable Private Messaging. 
I have enabled FORM based emailing so your emails remain private and hidden.
To use this, you must enable emailing.
1. Click the "usercp" button at the top left.
2. Click the "Edit Options" link.
3. Find the "Messaging and Notification" box and enable emails from both Administrators and Other members.
4. Click the "Save Changes" button at the bottom of the page.
To email someone, left click the round icon found to the right of their Forum/Usename in any thread. In the menu that appears, click the "send email to [usename]". A Web Email Form will appear that allows you to enter your Subject and message.
You do not see their email address. The Forum will email them. If they reply, it will come back to the Forum and the Forum will send you an email. No one sees anyone's email address. That is consistent with MTU's Privacy Policy.
Enjoy!
