On Fri, Mar 26, 2004 at 10:04:53AM -0800, Hallam-Baker, Phillip wrote:
PM> No, I think it's much closer to preregistering a small,
fixed set of
PM> operators who are willing to relay your call.
Sorry, no. The relevant MTA is the point of access into the mail
distribution service. That's equivalent to a telephone handset.
Without appologies - NO! WRONG!
The equivalent of a telephone handset is the mail client. Note that
I use that term not 'MUA', the user knows it as Outlook, or Eudora.
The user is not aware of the MTA, any more than they are aware of the
'exchange' they might hypothetically be on.
[NOTE: Both of the following statements are from the perspective
of the receiving MTA, not the perspective of the relaying MX]
If we assume that an MUA shall not connect directly to a receiving MTA,
but instead shall always use a relaying MX for outbound mail, then the
MUA+MX is equivalent to the phone, because the identity ("phone number")
is bound to the MX, not the MUA (at least for purposes of RFC2821 checks
on the receiving MTA).
It's only in cases where the MUA connects directly to the receiving MTA
that the MUA itself is sufficient to be considered the "phone".
Mark C. Langston Sr. Unix SysAdmin
Systems & Network Admin SETI Institute