On Sun, 19 Dec 2004, Jochen Topf wrote:
Reading Dave Crocker's draft-crocker-email-arch-01 I started to think again
about the identification and differences between "email addresses" and
"mailboxes". In the draft, as in many other documents, both concepts are
essentially one, the email address is a "mailbox address".
I recognize the historical truth in this and the current email systems
have many vestiges of that school of thought, but nevertheless, I think it
is conceptually misleading. I am not sure where this discussion will lead
and whether this is important for the draft on email architecture, but
I'll send it to the list anyway and we'll see where it goes.
I agree with everything you say.
I have a very minor niggle, though.
It is the job of the MDA to do the actual transition between the "email
address space" and the "mailbox space". It translates email addresses
into mailbox names and delivers the mail.
Note that in this concept an forward/alias from one email address to another
happens in the MTA not in the MDA.
It's often the case that it isn't until the email address -> mailbox
translation stage in the MDA that the system finds out that the
destination is another email address instead of a mailbox. For example,
Sieve implementations can direct messages to mailboxes or email addresses.
MTAs can also to email address -> email address routing. I'm not sure if
this is an implementation artefact or an architectural feature. It's often
hard to distinguish between the MDA and MTA parts of email software.
Tony.
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