Re: Checking `Reply-To'

[Stainless Steel Rat <ratinox@peorth.gweep.net>]

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>>>>> "PA" == Per Abrahamsen <abraham@dina.kvl.dk> writes:

PA> I -- like many others -- have many email addresses that are equally
PA> valid from a technical point of view.  I prefer one of them, which is
PA> the only thing that distinguish it from the others.  My preferences
PA> (and these alone) thus makes it my "canonical" address.  So we do not
PA> really disagree.

If the mailbox specified in the From header does not point back to the
originating host or originating site's mailhub, then the address is not
canonical as far as RFC-822 is concerned.

If I send mail from peorth (my laptop) with "ratinox@ccs.neu.edu" as the
- From mailbox, it is wrong even though the mailbox is a valid mailbox,
because "ccs.neu.edu" is not a canonical name for peorth in any way, shape,
or form.  If I want replies to a particular mail to go to the
ratinox@ccs.neu.edu mailbox I should have ratinox@peorth.gweep.net in the
- From header and I would put ratinox@ccs.neu.edu in the Reply-To header.

ratinox@ccs.neu.edu in the From header would be a forged From header.

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-- 
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