The communications watchdog has issued a "formal warning" to Elders Real Estate Wollongong following an investigation that found the agency breached the Spam Act.
The Australian Communications and Media Authority said the real estate agent breached the Act by sending commercial electronic messages without an unsubscribe facility.
ACMA said it contacted "more than forty" head offices of real estate franchisors and companies last year to inform them of "key obligations" and "consequences of non-compliance" with anti-spam laws.
"This is the first enforcement measure taken against a real estate agent since an ACMA awareness campaign about unsolicited communications targeted at the real estate sector," said Chris Cheah, acting chairman of the ACMA.
Penalties of up to $1.1 million per day may be imposed by the Federal Court for repeat offenders of the Spam Act, ACMA said.