On Mon, Nov 14, 2005 at 10:49:06AM -0800, Dave Crocker wrote:
The current draft refers to a collectively-managed set of email components
as distinct from some other, independent collectively-managed set of
components -- as an Administrative Unit (AU). Examples might be a personal
MTA, as one AU, an email hosting service as another, an integrated service
(AOL, Yahoo, MSN, etc) as another, and so on.
...
We need *some* term, so that such references as "boundary MTA" can be
meaningful -- what is it the boundary of?
Last week, I was told to see whether an acronym might do better. Here is
my first candidate, with an eager request for anything better that folks
like:
People like to visualize. Often I see clouds to define borders. You can't
look through clouds. That's OK, as you hand the message over to the next
administrative unit you're not responsible anymore. You do not know nor
care what is in the cloud, or behind it. Easy analogy I'd say.
So: (A)dministrative, (B)order/(or: Boundary), (C)loud: ABC
Obviously the host serving as boundary MTA _is_ visible. It is on
the edge of the cloud.
Inside the cloud you can see your own servers.
If someone sets up (an) MX record(s), they hide behind those servers.
Those become, by definition, points where Mail is eXchanged between
clouds.
Not all servers on the border need to be MXes. There can be servers
on the edge looking outside, but not receive mail. Those _can_ send.
If mail is forwarded, it comes out of that cloud and goes into the
next. The next receiver cannot look through the cloud either, it
knows nothing about this message except that it comes from this cloud.
Alex