RFC822 compliance in modern mail clients?

[Stephen Hansen]

    This isn't entirely on-topic, but in the process of working on a lexical
analyzer for rfc822 (Yes, i know that the module rfc822 already has one),
i've been slowly reading over the standard and translating it into actually
Readable-By-Me reference notes, and I was wondering..

    Do any clients pay attention to headers  such as Resent-etc? Anytime
anyone's ever forwarded me something, its always seemed to come from them :)

    Just curious how much attention I should pay to it :)

--S