Re: Realisticness of header rearrangement

> > 
> > I just don't see the point of finding ways to trust filters outside
> > your own domain of control.  Inside your own domain of control, you
> > don't use the historical-format tags for anything other than, well, a
> > history.  For interpreting the result of your local filter(s) you use
> > fixed tags that are erased and then regenerated.
> 
> We're not necessarily talking about trusting filters outside of your
> domain, how do you make sure you trust your own filters? 
> 
> You've got an implicit list of local filters accessible to your MUA,
> which needs to be kept up to date (the MUA can't do this
> automatically, as it would have to be able to discover which filters
> to trust).
> 
> If your local filters want to cooperate, they'll have to be able to
> access this same list.
> 
> There's also the question of what is "your domain". If you get mail
> via pop3, does your ISP's spam filter qualify as "your domain"? If so,
> you'll need to be kept up to date when they change their spam filters
> around, so you can update your MUA settings.

My perspective is this:  you don't trust the historical filter trail
at all (these "tagged" or "filtered-by" equivalents to trace fields).
You trust fixed headers inserted by the filters that you know are
operating on your behalf.  You know that the filtering system that you
are taking cues from deletes all fixed headers before adding its own;
and you know that the filter that does this for you has a similar
requirement of any input that it uses.  The MUAs would take their cues
from one or more sets of these fixed filters of varying styles.  This
is what people are doing now, with headers emitted by spamassasin or
what-have-you.

Now, what happens when you move to a different environment, or the
filtering environment around you changes?  Both of those are
relatively easy to deal with at one level or another.

I think one problem with this discussion is that we are flailing around
with different suggestions for headers without having a common notion
of the overall environment or the goals for such headers.  Mine
is fairly simple (and perhaps naive-- I'm willing to have that
corrected if true):

 - trace headers are only for exposition to the curious;
 - fixed headers are for productive use.

mm