Mr Simpson said the invoices Mr Staples was seeking payment for relate to work that he commenced without EQC's prior approval.
"EQC is treating these invoices in the same way as we treat other situations where a customer chooses to do repair work themselves and then invoices EQC without first seeking EQC's approval. EQC does not pay invoices on a no questions asked basis."
Mr Staples said he was going to apply to the District Court to retrieve the email.
He said he wanted to use the information in it to support his civil action against EQC for not paying him money he says he is owed.
It was "bullying" tactics for the commission to involve the police, he said.
"If you owe someone $700,000, you better pay him, you don't call in the police and use bully-boy tactics. Get your cheque book out and send me a cheque."
He said he had a lot of support from the community.
Mr Staples said he believed EQC was not paying homeowners the right amount to have their houses fixed and he needed the email information to prove his claim.
He said EQC had "no right" to say they needed to give approval to work before agreeing to pay for it.
He had received legal advice that there was nothing in law requiring anyone to get approval before fixing their houses.
"This is something that EQC is doing off their own back - policy on the run."
Mr Staples denied he was breaching an agreement in asking the court to give permission to retrieve the email because the requirements in the agreement had expired.
"They stuffed up, they stuffed up as they always do.
"I'm not trying to distribute information, all I'm trying to do is gather evidence of the cases we are taking to court."
If the court did not grant him permission to retrieve the email, he would ask for it under discovery, Mr Staples said.
- additional reporting Rebecca Quilliam