RFC: User-Agent header

[Sebastian Spaeth]

On 2010-04-10, Carl Worth wrote:
> So I propose something like:
> 
>   User-Agent: Notmuch/0.2 (http://notmuchmail.org) Emacs/23.1.1 (gnu/linux)

That looks good to me. So I assume the correct strategy here would be
to:

1) have notmuch reply insert a header:

User-Agent: Notmuch/0.2 (http://notmuchmail.org)

2) have notmuch-reply.el (or whatever) add a setup mail hook that
searches for an existing User-Agent header and appends " Emacs/23.1.1
(gnu/linux)"  

One issue is again, such a hook would be message mode
specific, so gnus users might not appreciate that. Also when composing a
message via c-x m this would not work. So perhaps an all lisp solution?
Again, can we hijack message mode to add our own promotion header?
Or has the time come for a notmuch-message-mode that somehow inherits
from message mode? bremner said something about dynamic bindings that
would allow that.

Sebastian