Navigate to Data⇒My Settings⇒Who is online
A list of all users currently logged in to the system will be displayed, select the User(s) that you wish to send a message to using the tick boxes next to the User name(s) and click Send a Message
In the popup window, enter a title type the message and then press Send
The User(s) will be notified of the message immediately.
If you receive a message, a note will be displayed in the bottom right hand corner of your screen. Click on the note and then highlight the email to read the message