When you double-click on the MailBox icon in your Desktop window, a list of your messages is displayed. Remember, you know immediately if you have new unread messages because an Unread Flag will be displayed beside the MailBox icon. Your mailbox contains both your incoming and outgoing private messages. The summary lists the sender or recipient of the message, the size, the subject, and the date and time the message was written or received.
Threads are a message and all the replys written to that message.
A hollow flag means this is a message you wrote but which has not been sent. It could be a private message or one directed to a conference. A file icon indicates that the message has one or more files attached to it. When you double-click on a message line, the system brings up a window showing the contents of the message. If you want to send a response to a message you have received, there are two basic ways to do this.