Reading your Messages
To see the messages you've exchanged with other members, and messages sent to you, click on the in-tray icon in the main menu:
A drop-down menu will appear, showing your recent messages:
You can click on any of the messages to be taken to the conversation, or at the bottom of the popup, you can click 'View inbox' to be taken to a page with all your messages.
This page operates much like an email inbox.
You can view any of the messages by clicking on them and then responding via the box at the bottom of the screen.