David F. Skoll wrote:
John C Klensin wrote:
In either case, a formal handoff of responsibility for
the message occurs: the protocol requires that a server
MUST accept responsibility for either delivering a
message or properly reporting the failure to do so.
I think this is a simple rewording of a clear statement.
The only unclear thing to me is:
"...properly reporting the failure to do so."
Does everyone understand this to mean reporting the failure
to the sender (in the case of a non-null Return-Path) or to
some administrator (in the case of a null Return-Path)? If everyone
clearly understands it this way, then it's fine. Otherwise, we may
want to spell it out. Otherwise, someone might consider dropping
an e-mail and letting an administrator know about it to be
"properly reporting the failure".
How about:
In either case, a formal handoff of responsibility for
the message occurs: the protocol requires that a server
MUST accept responsibility for either delivering a
message or properly reporting the failure to do so.
A proper failure report MUST consist of a notification to the
sender of the message if the original message has a non-null
return-path, or a notification to an administrator of the
SMTP server if the message has a null return-path.
Or am I worrying too much? :-)
Hi David,
There is no server notification "message" requirement for NULL return
paths. That would be definitely be a server implementation (feature)
concept.
For example, you have two models for this:
Dynamic (SMTP transaction level) Notification
C: MAIL FROM:<>
S: 250 OK Null Accept for Local Notification Delivery only
C: RCPT TO:<unknown @ localdomain.com>
S: 550 Sorry, doesn't exist
Post SMTP Notification (No Local User Validation or Local Hosted Domain)
C: MAIL FROM:<>
S: 250 OK Null Accept for Local Notification Delivery only
C: RCPT TO:<localuser @ localdomain.com>
S: 250 OK
C: DATA
S: 354 Send Data
C: [upload data]
S: 250 Message Accepted
The post smtp processor handles the message. If not deliverable to the
local user or hosted domain, a bounce is NOT REQUIRED to be sent because
there isn't a return path.
Each implementation can handle that their own way. It is local policy
driven.
In general, if it passes some security layer (AVS, etc) then its may be
posted to some predefined local admin address or each trashed. But this
is not a requirement for SMTP.
Good Local Policy Feature for SMTP server to offer? Sure, but not a SMTP
requirement.
--
HLS