Josh Good:
> Old-style forwarding is when the forwarding MTA forwards the message
> re-using the original Return-Path in the SMTP envelope, instead of using
> its own address in the Return-Path. Because if the forwarding MTA uses
> its own address in the Return-Path while forwarding the email, SPF poses
> no problem at all.
>
> That old-style forwarding is out of style, and it is frowned upon
> nowadays.
DKIM works just fine across multiple hops of forwarding as long as
one does not modify the message in transit (someone said that DKIM
is hop-by-hop; they don't understand what DKIM does). If anyone's
DKIM verifier fails on this posting, let me know.
Wietse
