[elehack]

Simple, non-evil answer: because it would severely impede spam prevention. This extensive writeup has details: https://moderncrypto.org/mail-archive/messaging/2014/000780....

Long story short, to control spam, you basically have 2 options:

1. Control who can send messages 2. Inspect message content 3. Impose costs

Signal and WhatsApp chose (1). E-mail (and probably any federated protocol) requires (2) or (3), and there is no universally-adopted (3) for e-mail.

[jakeogh]

Their business model is to mine your mail. Spam censorship is just a feature that happens to fall out.

[ac29]

Google hasn't used email contents for ad targeting in a couple years: https://blog.google/products/gmail/g-suite-gains-traction-in...