An email marketer says new anti-spam legislation will not have much impact in New Zealand because most of the spam is coming from overseas.
On September 5, the Unsolicited Electronic Messages Act is being introduced to combat spam emails and text messages with a commercial nature.
Inbox Ltd, a New Zealand company specialising in email marketing and publishing, said the onus should fall on internet service providers to authenticate emails.
Its managing director, Jerry Flay, said the legislation would not affect how much spam New Zealanders get.
"There won't be a reduction in spam unless the email industry and internet service providers work together to implement authentication."
He said there would be "howls of outrage" from people when they realise their inbox is still fill of spam.
Mr Flay said marketers in New Zealand would be "severely damaged" because the legislation requires them to update their records which costs time and money.
But he did not think marketers were the problem.
The Department of Internal Affairs is the government body that will investigate complaints about spam from the public and act against spammers in New Zealand who are deliberately flouting the law.
Anti-spam unit manager Joe Stewart said the legislation will allow New Zealand to enter into international agreements to share information and pursue cross-border complaints.
He said the legislation enabled the government to stop New Zealand becoming a "spammer haven" by allowing it to fight New Zealand-sourced spam.
The Marketing Association of New Zealand chief executive Keith Norris said the legislation meant the government would be able to share information with overseas governments to "identify and eventually close down" the spammers.
"It is sending a signal to people who do not respect our individual privacy."
He said commercial messages would be defined as spam, unless there was some form of consent.
Run the Red, a leading New Zealand mobile service provider for information and entertainment, said it supported the legislation.
Run the Red director Ben Northrop said the legislation was supporting what was already in play.
"It keeps the industry in check."
He said it affected the whole industry when one company sent unsolicited texts or emails.
"We already have rules in place and have been for a while."
Complaints can be made at www.antispam.co.nz.