The mail is basically unparsable (hint: you can use a sane mailer even
with exchange servers :)).
Either way we need to get rid of buffer_heads, and another aop that
is entirely caller specific is unaceptable. That being said your idea
doesn't sounds unreasonable, but will require a bit more work and has
no real short-term need.
So let's revisit the idea once you have patches to post and move forward
with the more urgent needs for now.