Robinson's five-bedroom, 500sq m Killara Luxury Lodge on Ness Rd, inland from Kerikeri, was destroyed by fire just before midnight on September 9, 2011.
Robinson was charged with arson after his home burnt down, but the charge was withdrawn by police in the Whangarei District Court last year.
State Insurance declined Robinson's claim after concluding the fire was deliberately lit. In May 2013, Robinson emailed Mr Hlavac and suggested a settlement offer either immediately in confidence or openly through the media.
Two more threatening emails were sent that month. Robinson's threats included using a website to destroy IAG's reputation, unless his monetary demands were met.
Justice Duffy said Robinson was "headstrong and arrogant" and thought he knew better than his lawyers and he had done himself a lot of harm.
"You ignored legal advice. Now hopefully you can see that what you did was a mistake ... leave it in the hands of your lawyers from now on," she advised.
Seamus Donegan, deputy general counsel for IAG, read a victim impact statement in court.
He said it was not uncommon for people in testing circumstances to threaten the company with media action, but Robinson's threats and demands were "extraordinary".
"Our good name is everything to us," Mr Donegan said.
"We decided to refer this to the police."
Blackmail carries a maximum penalty of 14 years' jail, but in this case Justice Duffy noted Robinson had shown remorse, his threats did not involve violence and she did not consider IAG to be vulnerable victims.
She said his previous blackmail convictions had little weight as they were more than 20 years ago and, based on what evidence had been presented, were different to the ones before the court.
Robinson is now pursuing his claim against the insurance company through the civil court.