Emails

Hi, I am posting this for my friend who going through a divorce much different from mine. Her husband found an email that she attempted to send to another man. It was never sent. He confronted her about it, they never separated, he decided he wanted to stay married. He later broke into her email account and found some emails where she was conversing with another man. Nothing ever happened, whe never had sex with the man or anything. He forgave her again and wanted to continue with the marriage. They even moved out of state for a while, then a year and a half later he decides he wants to leave because of what she did. He could not get over what she did. Now it has been almost three years and he has threatened to use those emails against her in the custody hearing and the divorce. I thought there was a no fault law in NC. Could he use these against her three years later even after he forgave her, never left and continued on with the marriage. Is this considered adultery or does there have to be a sexual act involved? Please help she is scared out of her mind that it is going to hurt the child support ond alimony if she gets it.