Politicians and/or their staff generally monitor the letters pages of newspapers. As well, published letters can raise awareness of an issue among readers who would not otherwise be aware of it. Even if not published, your letter could be instrumental in drawing to the newspaper's attention that the issue is of public concern and should be reported on by their staff.
Keep letters short (most papers have a limit of 200 or 300 words) and include your name, address and phone number (newspapers generally will not print letters unless they are able to contact and confirm the sender).
Some addresses for emailing/submitting letters to editors are below (addresses can usually be found on the letters page of the newspaper):
- The Australian: [email protected]
- Sydney Morning Herald: [email protected]
- Daily Telegraph: http://www.dailytelegraph.com.au/news/opinion/letter-to-the-editor
- The Age: [email protected]
- Herald Sun: http://www.heraldsun.com.au/news/opinion/letter-to-the-editor
- Canberra Times: [email protected]
- Courier Mail: [email protected]
- Adelaide Advertiser: [email protected]
- West Australian: [email protected]
- Hobart Mercury: [email protected]
- The Saturday Paper: [email protected]
But don't forget about regional and suburban newspapers - your local MP will almost certainly also monitor these.