If you would like to send and receive Private Messages from users of GM's and Moderators then please enable this option in your account by following these instructions.

First click on the "User CP" option up top and proceed to the "Edit Options" side bar link. From there make your way down to the "Enable Private Messaging" option and check mark it on. Then just save and you should be ok to go.

This is a very useful feature and you should turn it on if it is not already. ^_~