Gordon Fecyk wrote:
One of the concerns raised with LMAP proposals is the fact that they
overload the MAIL FROM command.
Isn't that the intent?
I understand overloading a DNS record type - giving more meaning to a
record type than originally intended.
I'm not as clear on "overloading" a SMTP command, especially this one as
MAIL FROM is supposed to tell us who the mail is from and we're only
verifying that - at least as far as the domain part for most.
The MAIL FROM parameter does not tell us where the mail is from, only
the bounce address for that email. The assumption is that whoever is the
bounce address is, is probably the sender, but in many cases especially
mailing lists, that is not true. As a matter of fact in some protocols
such as SMTP AUTH, the sender's identity is passed in an SMTP extension
separate from the bounce address.
This of course depends on what the LMAP proposals are designed to do. If
they are designed to give domain owners ability to state which MTAs can
use their domains in the bounce addresses, that's fine but it should be
clearly stated as such and not be confused with the sender of the email,
which is unknown during the SMTP transaction.
Yakov