A new header icon has been added for users to quickly know when they have new unread SMS messages. This is an option that can be enabled within User Preferences > Home/Sys Wide. 

When enabled all unread messages from the past 7 days will show in the fly out. 

Clicking a new message will open the conversation in a pop up. 

Clicking 'See all SMS messages' will open another tab where a user will be able to filter the messages further.