Date: Fri, 14 Sep 2001 10:31:14 -0400
From: Martin W Sachs <>
I completely agree with your conclusion but I am curious about SMTP. When
I send an email, I send it to the email address that I know for the
destination. When I receive an email, the sender sends it to my email
address. Yet the header information may show that this email has travelled
through lots of intermediary mailers. I don't know how the routing
mechanism works but I do know that I don't have to care about it. I am
doing end to end addressing. And yes, it is below the level of ebXML but
it is an example of unreliable intermediaries.
Yes, I agree with all of this.
(If you're curious about how the email routing works, here's
the basic explanation I have:
Basically, the client does a DNS lookup for MX records, finds
the one of best preference (lowest number) that it can reach,
and sends the mail there. The server to which it delivers
either delivers the mail to a user (or user mail store), routes
it elsehwere based on local knowledge, or repeats the process,
looking for a server that is more-preferred than it is. There
are many subtlties, but the basic system is pretty simple.
See RFC2821 for full info; RFC974 for an earlier treatment.
