http://lpoaj76nfopd5lpinbskyqtroppamrzhhay3g4vvjm75st6ger34lbyd.onion/posts/2020/08/email-sucks.html
But, perhaps, spam is not an issue, and you just want to use it for private, end to end encrypted correspondence, and you do not care about self hosting? Well then, PGP/GPG seems great, doesn't it?