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Re: New Sieve extension "refuse" proposal - draft-elvey-refuse-sieve-01h

2004-02-27 09:18:52

On Tue, Feb 24, 2004 at 09:11:19PM -0600, Matthew Elvey (FM) wrote:
On 2/22/2004 4:23 PM, ned(_dot_)freed(_at_)mrochek(_dot_)com sent forth 
electrons to convey:

It's unavoidable for behavior to differ between an MUA and an MTA, if
there is support for a "refuse" action.

This presupposes that refuse is supportable on an MUA.

I didn't (mean to) communicate that.  What I meant to communicate:

It's unavoidable for behavior to differ between an MUA and an MTA, if
there is support for a "refuse" action (in Sieve when not on an MUA).

There are at least two different concerns that are being mingled,
I think:  one of script operating context, and one of portability
within a given context.  A script running in a MUA is in an entirely
different context than a script running on an SMTP server.  I believe
most portability issues only apply to scripts within a given context.
Personally I would imagine that an MUA script is written and maintained
differently than one that runs on an SMTP server-- which may or may
not be an MTA script (it could be an MTA script or an LDA script).
So I see no reason to want a particular script to run without edits
if it is put into a different context (MUA vs MTA).

The question is whether an end user can write a server-side script
that will operate whether or not that user knows if the script will
be invoked by the MTA (so that SMTP-time refusal is possible) or
by an LDA after the message has already been accepted at SMTP time.
I believe it's valuable to have this level of portability.  Even within
the same mail server (or server farm) the operating mode might change
from time to time.  It would be good if the script could accomodate
such a change, and it would be good to minimize the amount of work
necessary to refit a script when moving from one environment to another.
This would benefit both script writers and system administrators.

This is not the only situation where it would be useful to have a more
than just the "require" facility.  (I'd like to be able to have a
script that can be conditionalized according to what extensions are
available, or according to what mode or context the script is
operating under.)  Solving that is not appropriate here, however such a
solution would be applicable to "refuse".  Without this, I believe it
makes sense to try to make "refuse" operate in a server context,
whether or not the script is running at SMTP time.