A summary of the 3 main components of the Australian anti-spam laws (The Spam Act 2003) are as follows (in completely non-legal speak!!):
1/ you must obtain prior consent, even to send one commercial email or SMS, to a contact.
2/ you must identify yourself as the sender, including your name, company name, ABN, address and phone number.
3/ you must make it easy for people to unsubscribe.
Enudge implements 2/ via the mandatory information at the bottom of each email, and 3/ with the automated unsubscribe feature. You can also repeat the unsubscribe link within the body of your email to make it even more accessible.
With regard to consent, it is a requirement in our terms and conditions, that you agree to ensure you obtain consent from all your contacts located in Australia prior to sending messages to them. Consent can be implied if you have had a prior transaction with a person in relation to the same product / service compared to the content of your messages. The onus of proof of consent is on you, the sender, so we strongly recommend obtaining specific written / electronic consent prior to sending your messages.
Even is your email practices are compliant with the anti-spam laws, if your contacts think you are spamming them, that's still bad. This presentation given by Heather Maloney provides 3 key strategies for ensuring that your contacts don't perceive your emails are spam (even when they are not).