This information is provided from the Parliament of Australia website – https://www.aph.gov.au/Senators_and_Members/Guidelines_for_Contacting_Senators_and_Members.
Contacting Senators and Members
How to address Senators and Members
Contact a Senator or Member electronically
Senators and Members individually decide their preferred web based contact method. To contact your Senator or Member first find their home page using the below search tool. Their home page will contain their contact details and best method of contacting them.