[FunnyLookinHat]

> > Spam checking on content isn't possible

> This is probably your best point. It's definitely harder to do well

I think it's possible, just slower and more complex (like search) - and would have to occur upon unlocking your inbox.

[amenghra]

You can mostly get rid of spam by requiring the sender to perform a proof of work if they aren't in your contacts list. I.e. whitelist of senders + proof of work or some kind of configurable per domain quota/proof of work.

[askmike]

I guess that gets rid of all other email as well..

[dexterdog]

How often do you get email from somebody that you've never gotten email from before?

[gtCameron]

Exactly once for each contact that has ever sent me an email

[ardivekar]

Maybe a two-way 'add contact' feature would be useful, like a facebook friend request.

[eriknstr]

Sure but then it's not standard e-mail any longer.

[dexterdog]

I'm talking about now going forward. There are plenty of ways to make a person opt-in the first time they send you something. That process gets rid of more than 99% of spam.

[carussell]

This feels... parochial.

It wouldn't be so good if email turned into Facebook, where you can only contact somebody if the circuit has been established beforehand (i.e., both parties friend each other). What happens if this is the point of initial contact, and there's no other way to get in touch? I have to conspicuously friend this person from my otherwise dormant account and then not think about whether they're going to feel weird when I unfriend them later on?

I sent an unsolicited email a couple weeks ago. Academic-type, self published, personal webpages where I saw something that needed fixing, and so I did. There was no CMS, just a static site—and not the sort where you're running markdown sources through a generator and have a whole Git hosting service apparatus intertwined with hooks sunk into it. Plain, legacy HTML. I saved a local copy to my machine, made my changes, and mailed them in. They happened to be machine-readable patches, given the recipient, but it could have just as well been a message written in natural language. The changes were made, I was thanked, and done.

I'm still upset that in the 90s I could get in contact with almost anybody by looking in the phonebook, but when I tried doing that a few years ago for an old coworker, it was hopeless. Getting the listings for a city you've moved away from can prove to be harder than it seems, even when you know they have a landline.

These are the kinds of things you lose when you assume the world is already fixed in the form that it should maintain going forward.

[sandworm101]

From every client that a former client has sent my way. 50% of my clients introduce themselves with some variation of "Something happened, Bill gave me your name. Help!".

[Groxx]

Does anyone actually use e.g. hashcash though? I love the concept, but it's useless if nobody can use it.

[em3rgent0rdr]

I don't think Spam checking should be a concern since most spammers aren't going to encrypt their spam.

[e12e]

Might even flag not just plaintext email, but quarantine all mail from unseen senders / public keys. Should make spam filtering much easier.

[wheelerwj]

How often does spam come encrypted with your public key anyways?

[Neliquat]

Much more often if this is used as a spam measure.

[e12e]

Maybe. Still requires a re-encryption of the symmetric session key for every recipient - effectively proof of work.

"stretching" the equivalent of rsa(session_key, public_key) might be feasible?