terry(_at_)ashtonwoodshomes(_dot_)com wrote:
You do not understand the problem. The difficulty with
forwarding occurs at the receiving sites, not the sending
sites that publish Sender-ID records.
There is no such thing as a "receiving site" here. Or rather, the term is
used rather misguidedly to denote a site who forwards. If I send mail to a
'receiving' site, which forwards that mail, then that site is simply another
hop in the sender chain.
If you use -all you must never send email to an
alias-fowarding address -- but you have no way
of knowing which addresses these are.
This 'problem' is hardly new; it is covered in section "Does SPF break email
forwarding?" in the SPF FAQ, at:
http://spf.pobox.com/faq-old.html
The answer is given there, too. Worth quoting is this one:
If you don't have procmail, the .forward could instead just say
"|/usr/sbin/sendmail -oi -f nobody(_at_)intermediate-domain(_dot_)com foo(_at_)bar(_dot_)com"
Professional forwarders should implement SRS. It does not suffice for them
to be SPF compliant on the receiving end, yet to omit implementing the
necessary rewriting scheme (or use SUBMITTER, once it comes into fashion) on
the sending part of the equation.
- Mark
System Administrator Asarian-host.org
---
"If you were supposed to understand it,
we wouldn't call it code." - FedEx