Another email from the mayor to a cat colony supporter read: "This is a decision of the community board, not council. If your cat-loving mates really wanted to change things instead of threatening not to come perhaps they should have threatened to come. I notice most come from US which quite happily attacks and kills humans all over the planet."
Mr Brown has acknowledged calling someone a dickhead, but claims it was in response to another email from a different correspondent's "fairly aggressive" email containing an obscene remark.
Many writers seemed to believe he was responsible for the cat colony decision, even though he kept pointing out it was up to the community board. People offended by his emails had no sense of perspective or humour, he said.
Mrs Henry told the Advocate she was initially "astonished and very shocked" by Mr Brown's email.
"Then I got enraged. However, I refuse to step down to his level. I find it interesting that he demands that we stop killing people in what is a very unpopular war in our country, but it's acceptable for him to think cats are expendable."
At least two community board members subjected to a barrage of hundreds of emails, some of them threatening and abusive, have complained to police.
