This sounds like someone a few of us are familiar with (I'll just leave it at that but I think a few of us have a guess here).

Before you all jump on calling her psycho remember some dudes are masters at manipulation and gaslighting. Sounds like he's still trying to mess with her, even though she's now his ex. Great guy. She should consider it a wake up call and you should probably quietly back away so you don't get caught up in their drama. Why does she care what he's heard, and even more so, why does HE care? They need to move on.

Geez folks, get off the mental illness stump. He hacks her email. Stop being so dramatic everyone. She doesn't realize she's being hacked. Get a grip.