I'm curious to know why this did not affect Office 365 / Exchange Online. I used to work for a law firm which ran on-premises Exchange, but had OWA running beh

I'm curious to know why this did not affect Office 365 / Exchange Online. I used to work for a law firm which ran on-premises Exchange, but had OWA running behind a VPN. I remember finding it extremely inconvenient at the time. But they're the ones laughing now.