Message from Australia, Melbourne, returned (5)
I believe the answer is:
'message' is the definition.
(email is a type of message)
'from australia melbourne returned' is the wordplay.
'from' says the answer is hidden in the clue.
'returned' is a reversal indicator.
'liame' is hidden in the letters of 'australia melbourne'.
'liame' backwards is 'EMAIL'.
(Other definitions for email that I've seen before include "Send one online" , "Digital message" , "Spam perhaps" , "Electronic communication" , "Messages between computer terminals" .)