IPv6 isn't SMTP

[blake at ispn.net (Blake Hudson)]

Barry Shein wrote the following on 3/27/2014 2:06 PM:
>
>
> I suppose the obvious question is: What's to stop a spammer from
> putting a totally legitimate key into their spam?
>
It's entirely likely that a spammer would try to get a hold of a key due 
to its value or that someone you've done business with would share keys 
with a "business" partner . But ideally you'd authorize each sender with 
a unique key (or some sort of pair/combination). So that 1) you can tell 
who the spammer sourced the key from and 2) you can revoke the 
compromised key's authorization to send you subsequent email messages.

There's probably some way to generate authorization such that each 
sender gets a unique key or a generic base is in some way salted or 
combined with information from the individual you're giving your 
authorization to such that the result is both unique and identifiable.

--Blake