Re: a few short notes

Martin Duerst wrote:
> 
> At 16:56 04/02/01 +0100, Iljitsch van Beijnum wrote:
> 
>> Mandatory authentication is also a bad idea IMO. Obviously 
>> authentication is very important and must be supported so that people 
>> who only want to receive mail from verifyable sources get to implement 
>> this policy, but that doesn't mean that we should force *everyone* to 
>> use such a policy.
> 
> 
> I tend to disagree. *I* don't want you to receive a message that is faked
> and pretends to come from me, but doesn't. Even if you don't care, I do.
> I would strongly prefer a system that would not allow this. And my gut
> feeling is that most users would be with me on this.

I think the hard question is what level of "authentication" to require.
I am pretty sure 99.99% of users want better protection against spoofed
addresses than we currently have. But I am not sure they are willing to
go as far as mandating a global PKI of all e-mail users. So what's left, then?
Just verifying the two domains but not the users? Self-signed certificates
and ensuring that all messages from the same address come from the same
entity, but not ensuring that the claimed identities are really correct?
Weak form of sender address verification through asking the sender's mail
server to check the claimed address can actually receive messages and that
the message ID is valid? Something else, what?

--Jari