[PATCH] parser: Unmangle From: headers that have been mangled for DMARC purposes

[Jeff King]

On Fri, Oct 11, 2019 at 10:01:23AM +1100, Andrew Donnellan wrote:

> > This might provide an alternate solution (or vice versa). I kind of like
> > this one better in that it doesn't require the sender to do anything
> > differently (but it may be less robust, as it assumes the receiver
> > reliably de-mangling).
> 
> Yep, it's less robust - but OTOH there's always a long tail of users stuck
> on old versions of git for whatever reason and having some logic to detect
> DMARC munging may thus still be useful.

I think the two features would work together nicely out of the box: if
somebody has an in-body from, we'd respect that before looking at email
headers anyway. So senders who do the extra work will be covered, and
checking other email headers would just improve the fallback case.

-Peff