Re: header-munging

[Keith Moore <[e-mail]>]

> > + The message may lack a Date field.  The ISP's MTA can't reliably 
> >   supply a correct one, because it may be (with high probability) in a
> >   different timezone than the sender.
> 
> You're making two unstated assumptions here.
> 
> First, what does ``Date is correct'' mean? Here are two choices:

Ideally, the timezone reflects the sender's time zone, and the
date+timezone reflects the correct real time.

If that can't be done, then the timezone should be a valid timezone
(-0000 is fine), and the date+timezone should reflect the correct real
time.

But Date can't be guessed at by the MTA in any event, because it's the
date that the message was written, not the date that the message was
submitted.

> Second, even if you insist that the Date show the sender's time zone,
> what makes you think that the ISP's local time zone is incorrect?

It might or might not be.  But it doesn't work in the general case.

> Einar's point is that the ``MTA'' in this case _is_ the sender---it's
> really part of the MUA.

And my point is that the MTA *cannot* act on behalf of the user in
this case, becuase its configuration is not under the user's control.

> You might object that the ``real sender'' is some human who is perhaps
> in a different time zone. Who says? What business do you have peering
> behind the sender's mailbox? 

What business does the MTA have guessing at information that should be
supplied by the sender?

> If a human dials in from one time zone to another, are you going to
> tell him that he can't use his work zone on his e-mail?

The sender can use whatever timezone he wants, at his own peril.
Having the MTA supply the timezone is a different matter.

Keith