ietf-mta-filters
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Re: bounce, mta, & mua (was Re: sieve draft)

1997-11-04 13:37:54
On Tue, 4 Nov 1997, Bart Schaefer wrote:

} On Sun, 3 Nov 1996, Tomas Fasth wrote:
} 
} Rationale: I don't understand the difference between MTA and MUA filtering.

I see two differences:

1.  An MTA may not have access to all the UA's mailboxes.

2.  An MUA can't reject/reroute at the transport protocol level.

Ok; I never considered SMTP-level filtering seriously.  Which is why there's
an implicit assumption that the agent has the entire message.

The significant difference is that, even if the envelope sender in the
Return-Path is correct, the POP3 client has no access to the envelope
*recipients*.  In an ideal world, that makes little difference, because
every recipient has his own POP3 maildrop.  In the real world, POP3 drops
are sometimes overloaded to delivery messages to an entire domain, e.g.
as a "replacement" for UUCP.

Of course, there's little the Seive language can do about that, except
to make it easier for the ISP in such situations to provide server-side
filtering.

How do sites like this handle mailing lists, BCCs, and the like?

Should Sieve handle this?  (I don't want to, but should it?)

} Would making "bounce" optional help?

I don't think so.  One could still construct and send a DSN using other
seive tools, so making it optional just makes it more difficult to do
the action, not impossible.

OK; I was suggesting this as a policy choice as much as a technichal choice.

-- 
                                           Tim Showalter 
tjs(_at_)andrew(_dot_)cmu(_dot_)edu