Cant add a user

Cant add a user

Hi!
I have a user with the e-email contato@gaiapaisagismo.com.br but when I try to add karine@gaiapaisagismo.com.br it says that the user already exists. I refresh the page and the user is in a invitation list, so I removed it.
How can i add a user karine@gaiapaisagismo.com.br ?