You may double-click on a message to view the contents. From the Message tab you may open (if the proper viewing agent is installed) or save the message or attachments to disk.
The Properties tab shows various properties about the message.
Created Date: This is set by the sending messaging system and is stored in the message header, which Retain reads and stores.
Delivered Date This is set by the receiving messaging system and is stored in the message header, which Retain reads and stores.
Stored Date: This is set by Retain when the message is stored in Retain.
Expiration This is set by Retain, if that feature is set as part of Job | Core Settings.