The Commonwealth Bank has paid a record $3.55 million penalty after it was found to have breached Australia's spam laws.
An Australian Communications and Media Authority (ACMA) investigation found the bank sent more than 61 million marketing emails to customers that unlawfully required them to login in order to unsubscribe.
It sent a further four million marketing emails that did not have a functioning unsubscribe facility.
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The bank was also found to have sent more than 5000 marketing emails to customers who had asked to unsubscribe from these messages.
ACMA chair Nerida O'Loughlin said companies must give people the option to unsubscribe from marketing messages and must make it easy to do so when consumers want to exercise their rights.
"The scale and duration of the breaches by the CBA is alarming, especially when the ACMA gave it early warnings it might have some issues and the steps it took were ineffective," she said.
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"The failure to fix the issues shows a complete disregard for the spam rules and the rights of its customers."
The $3.55 million fine is the largest penalty ACMA has ever issued over spam law breaches.
Commonwealth Bank has also entered into a three-year "enforceable undertaking", which will involve an independent review of its e-marking practices, along with regular reports to ACMA.
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The bank said it had self-reported the issues to ACMA as part of an "ongoing engagement" over unsubscribing issues.
"We acknowledge and accept the findings of ACMA's investigation into CBA's compliance with certain provisions of the Spam Act," CBA group executive marketing and corporate affairs Monique Macleod said.
"We apologise to all customers impacted by these issues which should not have occurred. We've fixed the problem and are making changes to ensure it doesn't happen in the future."
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