On Feb 22, 2010, at 1:58 PM, Florian Weimer wrote:
> * Steven Bellovin:
>
>> Right; I was not seriously suggesting that the DNS was the right
>> spot for it. I am seriously suggesting that a redirect mechanism --
>> perhaps the email equivalent of HTPP's 301/302 -- would be worth
>> considering. Then, of course, there's problem of upgrading the
>> $\aleph_0$ mail senders out there to comply...
>
> There's already SMTP support for this, see RFC 5321, section 3.4.
> This has been carried over from RFC 821, which already contain the
> 251/551 response codes.
Thanks; I'd forgotten about those.
>
> However, this is still a public database for which you cannot charge
> access, so it's not the solution we're looking for.
>
--Steve Bellovin, http://www.cs.columbia.edu/~smb
