Re: header rewriting, was MARID charter and using 2822 data

> Perhaps we can say that any MSA/MTA that rewrites headers is taking
> responsibility for the message and should be prepared to vouch for
> it if it goes out via SMTP again.
Perhaps, or maybe - the last entity to modify the message (except by merely
adding trace data) must be able to vouch for the message.

Incidentally, I'd hope that "vouch" would mean either; assert something
about the source of the message and be able to provide some evidence; or to
take responsibility for the message.