The federal government will consider mandating all of its agencies to forward any correspondence that may raise national security concerns to ASIO.
It follows a recommendation made by NSW Coroner Michael Barnes, who delivered his findings into the deadly Lindt Cafe siege in Sydney on Wednesday.
The man responsible for the act of terror in December 2014, Man Haron Monis, wrote a number of letters to senior government figures between 2007 and 2014.
A letter addressed to Attorney-General George Brandis two months before the siege stated: "I would like to send a letter to Caliph Ibrahim, the leader of the Islamic State, in which making some comments and asking some questions. Please advise me whether the communication is legal or illegal."
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The Monis letter was passed on to the attorney-general's department's national security law and policy division.
A month later senior official Karen Horsfall replied to Monis.
She noted Islamic State was listed as a terrorist organisation, but that the department did not provide legal advice and could not specifically address the legality of his proposed actions.
Mr Barnes, in his 495-page inquest report, said there did not appear to be an effective policy in place to require the commonwealth bureaucracy to forward concerning correspondence to ASIO.
He recommended the attorney-general develop a policy to ensure such letters should be referred to ASIO and an agency known as the Fixated Threat Assessment Centre - which currently only exists in Queensland.
"If the FTAC system had existed in NSW and Monis' letter to the attorney general had been referred to it that letter could have been placed in its proper and complete context," he said.
"That, in turn, would have permitted the hyperbolic escalation of Monis' 'warning behaviours' to be identified and then addressed."
Senator Brandis, addressing a Senate hearing on Wednesday, noted the coroner did not make any findings adverse to the Australian Defence Force, Australian Federal Police or ASIO but welcomed the constructive recommendations.
"The government will study (them) closely and as a matter of high priority, and which will be acted upon as appropriate," he said.
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Senator Brandis said his department had routinely referred correspondence that might raise national security concerns to ASIO - at his behest - since 2015.
"In light of the coroner's recommendation, we will, of course, consider whether to extend such procedures more broadly across government."
The hearing was told that, following a Senate inquiry in 2015, officers from his department sought assurances from other agencies that they have procedures in place to deal with letters of that kind.
But they did not mandate a policy to be deployed across government.
Earlier, Prime Minister Malcolm Turnbull assured Australians that agencies were working tirelessly to keep them safe.
"We do that by destroying Daesh in the field in the Middle East and by destroying their networks here at home," he told parliament.
"We continue to use every avenue available at our disposal, providing additional resources whether they be financial or legal, whether it relate to signals intelligence or human intelligence or hard power."
Since September 2014, when the threat level was raised to probable, there had been 64 arrests for terrorism offences and 12 major plots disrupted.
