Let's try this: To send a Private Message:
1. Make sure you are signed into the Communities page.
2. Click the message count or envelope icon to go to your Private Messages Inbox.
3. Click Compose New Message.
4. Enter the recipient's name in the Send to area.
5. Enter the subject for the message in the Message Subject area.
6. Type the reply in the Message Body editor.
7. Then click Send Message