Re: header-munging

["D. J. Bernstein" <[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:

  (1) Date communicates the correct real time.
  (2) Date communicates the correct real time and the correct time zone.

Either choice is a plausible interpretation of RFC 822. #1 says that the
time zone is merely part of the encoding; #2 says that it's crucial
information. (What would #2 mean for a laptop flying between zones?)

You may recall that this issue was discussed on DRUMS, and that the most
recent date-time spec, distributed in April, received no objections.
That spec says #2 but provides a simple way to revert to #1---a time
zone of -0000 means ``I don't know my time zone.''

Under that spec, the ISP's MTA _can_ reliably supply a correct date.


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

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? 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?


---Dan