[ih] Some Questions over IPv4 Ownership

[Dave CROCKER]

On 10/15/2010 12:12 AM, Jack Haverty wrote:
> If "jack at 3kitty.org" is the example of forwarding you have in mind,
> that's not how it works.  When I change providers, I move my 3kitty.org
> service from one provider to another,
...
> I do have a bunch of xxx at 3kitty.org mailboxes, and they all must move
> together.


You are emulating a version of exactly the service I described towards the end 
of my note, modulo the extra forwarding hop. It's key feature is that it is 
independent of ISPs and it does not require their cooperation.

However, as you note, all of the mailboxes must move together:  granularity is 
at the domain name level, not the mailbox level.  To get per-user granularity, 
you have to encode it in the domain name, given the way email routing works.

The reason you can have "direct" routing, without having to go through a 
forwarder is that you control the DNS MX record.  In effect that means an MX 
record per "customer", if not per "mailbox".  Again, that's doable today and it 
is done today.  The challenge is scaling that model up to a mass market.  In 
effect, it means an MX per user (or maybe per family).  Yuch.

d/

ps.  I figure you're still unhappy we didn't adopt your encoding scheme when we 
did RFC 733...



-- 

   Dave Crocker
   Brandenburg InternetWorking
   bbiw.net