In the top nav bar, click on the "Inbox" dropdown. It will expand.
Click on the ( Menu) icon on the top right corner of the page. The menu will expand.
Then click on the dropdown that says "Inbox". It will expand.
Then click on Mailbox in the list of links.
A list of your incoming messages will appear.
To view a message, click on the subject of the message.
A NEW message (that you have not opened yet) will have a yellow background, and will have a icon to the left of it
A message you have OPENED will have a white/gray background.
A staff message will always have a red stamp on it that says "CS Staff". Like this: