Click on the Messages tab icon in the top right corner of the window to open the Messages panel. 

Here you can view all the messages you have sent or received. You can also send new messages as well as delete or archive existing ones.

You can send messages to a group / role or to users who have permissions on your profile / database.

You can filter your messages by subject, content or model name. 

You can also sort any column in Inbox, Sent or Archive tab.