When you are satisfied that the message you're managing is resolved you can close the message by clicking the red button labelled 'Close'. You will then be asked to add an optional closing note before clicking the 'Close' button in the pop up. 

Once closed, the message is removed from view and can only be accessed by your organisation’s admin account holder or by the member of staff who logged the message. 

See this in action! 🎬

If, after you have closed the message, the employee wishes to respond within the same message they can reopen the message by replying again.