Am 17.07.2017 um 09:48 schrieb Alex JOST:
> AFAIK Authenticated Received Chain (ARC) was designed for exactly this use
> case. Wondering if anyone has some experience with it or knows if Gmail is
> already honouring ARC-headers.
yes, there are multiple ARC implementations between alpha and production state.
a good entry for further information is http://arc-spec.org/
I personally work with OpenARC which is more alpha state.
At IETF 99 there was a Hackathon last weekend. People also worked on ARC.