from: Australian Defence Force website: http://www.defence.gov.au/people/message_to_troops.htm

Messages to the Troops

Australians are encouraged to send goodwill and messages support of a general nature to Australian Defence Force sailors, soldiers, and airmen and airwomen who are serving on operations around the world.

The text of e-mail messages may be reproduced on Defence websites and in social media. In this way your message may be read by a greater number of ADF members and their families. Your personal details will not be published.

Please include your name, suburb and state on your message:

e-mail to: messagestothetroops@defence.gov.au
Please include "Message to the Troops" in the subject line of your email.

Postcard to:
Messages to the Troops
Media Section
39 Personnel Support Battalion
Building 217
Randwick Barracks
NSW 2031

Please do not send enveloped letters, or parcels addressed to individual ADF members.