https://www.privacyguides.org/en/email/

Normal email is unencrypted when it’s on the wire in transit. (Nowadays they use SSL between servers, but it’s totally readable by every server in your pathway. Which isn’t much better ). The best you can hope for email is to encrypt it and store it at rest once it arrives at the server. If you self host the server you could have one way encryption enabled. If you don’t want to self host the privacy guide options are pretty good.

Don’t have any conversations via email if you can avoid it. Prefer end-to-end encrypted platforms like signal instead