However Mr Frost said: "It doesn't seem they've moved far enough in the right direction."
Internal Affairs general manager of identity and passports David Philp acknowledged the department had breached the privacy of the affected applicants due to human error.
"We realised we had made the error immediately after it occurred and took action to deal with it.
"We are certain that beyond the email address no other personal details have been disclosed.
"We are extremely disappointed that this issue has occurred and will be reviewing the process to make sure it does not happen again.
"We have written to each affected applicant and apologised for the privacy breach." Mr Philp said the department took privacy issues very seriously.
A spokesman for the Privacy Commission said the organisation had been notified by department about the email breach.
Privacy breaches
August 2011: An ACC staffer accidentally emails former National Party insider Bronwyn Pullar information about 6700 claimants.
October 2012: Blogger Keith Ng reveals private records including vulnerable children's care home addresses and medical prescriptions are available through public computer kiosks at Work and Income branches.
March 2013: Details of 80,000 earthquake claims mistakenly emailed to a blogger by an EQC staffer.