On 19 Jun 2020, at 13:38, Dave Crocker wrote:
The description of what a Mediator might do is not incompatible with
also viewing it as having characteristics of a publisher:
### [5.3](<https://tools.ietf.org/html/rfc5598#section-5.3>). Mailing
Lists
...
In addition to sending the new message to a potentially large
number
of new Recipients, the Mailing List can modify content, for
example,
by deleting attachments, converting the format, and adding
list-
specific comments.
Fair enough, but as you mention below, in the case of the common mailing
list, the intent is simply to redistribute the message with minimal
change (hence the retention of the Message-ID: and the From:). That
said, I do disagree with the reasoning given with regard to why
5321.MailFrom has changed: It's not because of the authorship, but
rather because it is responsible for the submission onto the network,
just as the ReSender is in 5.2.
Note that in terms of email transport, it is posting a new message.
Strictly in terms of transport, yes. But in terms of the layer above
(the 5322 layer), it is usually the same message; see the second Note:
in RFC 5322 section 3.6.4:
Note: There are many instances when messages are "changed", but
those changes do not constitute a new instantiation of that
message, and therefore the message would not get a new message
identifier. For example, when messages are introduced into the
transport system, they are often prepended with additional header
fields such as trace fields (described in section 3.6.7) and
resent fields (described in section 3.6.6). The addition of such
header fields does not change the identity of the message and
therefore the original "Message-ID:" field is retained. In all
cases, it is the meaning that the sender of the message wishes to
convey (i.e., whether this is the same message or a different
message) that determines whether or not the "Message-ID:" field
changes, not any particular syntactic difference that appears (or
does not appear) in the message.
Mediators really have complete freedom to do whatever they want. If
describing the full range of what a publisher might do, it would cover
the same range.
Well, "complete freedom" in the sense that no Internet police prevent
such actions. But for most mediators, large substantive (for interesting
definitions of "substantive") changes are outside of the scope of their
definitions, and would probably invite someone to say, "That's not being
a mediator." Certainly that would happen in the case of an alias or a
resender.
But typical mediators are trying to maintain a sense and ability for
the original author and the final recipient to experience an
end-to-end message exchange.
Yep. That's the point I was trying to make.
The degree to which the mediator asserts itself more visibly to the
recipient is probably the degree to which it looks more like a
publisher and less like a simple relaying service.
And eventually, I would contend, less like a mediator.
pr
--
Pete Resnick https://www.episteme.net/
All connections to the world are tenuous at best
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