No s/mime, no pgp, so the hackers get everything nice and neat in plaintext. Not sure why we think email encryption is optional nowadays, especially for sensitive communications.
Based on what I know, my impression is that email is significantly worse, and somehow I'd never considered that. But I'm not sure if I'm missing something...
Contrast with more recent messaging protocols (e.g. iMessage, WhatsApp) where the server doesn't have access to the message, they're decrypted on the client (while potentially also authenticating the sender).