Roger Moser wrote:
I think we should do it in a way that SRS rewriting keeps
SES signature clearly visible and the other way around
I don't agree. SRS should never touch a signed envelop sender
Here I would disagree with you. SRS is something the receiver
does, he's free to forward his mail in any way he likes. It's
his mail, he can check a signed MAIL FROM, or ignore it, and if
he forwards his mail, he can sign his own MAIL FROM, or use an
unsigned MAIL FROM. He can even (ab)use the original MAIL FROM
if the destination does not check SPF or uses a white list.
As soon as the mail leaves the "area of responsibility" of the
first MX it's not more the mail of the sender, it's the mail of
the receiver. Like a mailing list with one subscribed member:
The receiver is the owner of this mailing list. No MAIL FROM
interpretation with registered heuristics, please. Bye, Frank