The company behind the GraysOnline shopping websites has been slapped with a record $165,000 fine by Australia's communications regulator after sending hundreds of thousands of emails that breached the Spam Act.

The fine is the largest ever handed out and the 26th the regulator has issued outside of court since the Spam Act was legislated almost 10 years ago on December 12, 2003.

Fined: GraysOnline.

In court, the largest penalty the regulator has ever received was $24.25 million, which was imposed on Scott Gregory Phillips, along with several others in 2010 who established fake dating website profiles to obtain mobile telephone numbers of genuine dating website users.

An Australian Communications and Media Authority (ACMA) investigation found Grays' decision to treat an email campaign introducing its GraysEscape website as not promotional was incorrect.