notmuch reply From:-guessing heuristics

[Michael Hudson-Doyle]

Hi all,

I have a specific example where "notmuch reply" does not set a useful
from: header.  The set is:

1) I have a google apps-for-your-domain address,
   michael.hudson at linaro.org

2) There is a group/alias, validation at linaro.org that only accepts mail
   from members

3) michael.hudson at linaro.org forwards to michael.hudson at canonical.com,
   from where I get email with offlineimap.

4) michael.hudson at linaro.org and michael.hudson at canonical.com are both
   configured as addresses in ~/.notmuch-config with the linaro.org
   address being primary.

When I reply to a mail to validation at linaro.org, the guessed address is
michael.hudson at canonical.com and unless I change it, the reply bounces,
which is obviously a bit annoying.

Looking at the headers (and the notmuch source),
michael.hudson at canonical.com seems to be being found in the Received
headers.  michael.hudson at linaro.org is not in any Received header, which
is a bit strange, but in any case I think the code would find
michael.hudson at canonical.com first (would it perhaps make more sense to
search backwards through received?  An earlier header is probably closer
to what was intended, in some sense).

michael.hudson at linaro.org does appear in a Delivered-To: header, so
maybe those could be considered (it seems that some MTAs add a
Delivered-To header from the envelope address, so it would have some
legitimacy)?  It would work in this case, but only because the
Delivered-To that the canonical.com MTA adds is an internal address
that's not configured as an address for me in notmuch...

Alternatively, *I* wouldn't mind if notmuch stopped trying at all hard,
and just used the primary address if there was nothing matching in
to:/cc: but I guess that wouldn't work on mailing lists at all...

Hm, I guess I've argued myself around to thinking that considering
Delivered-To as a source of potential from addresses would be an
improvement.  What do you guys think?

Cheers,
mwh