ml ml:
> Can i also set the original sender address as the address_verify_sender?
> I wasnt able to find anything in the manual :-/
Wietse:
> It is not documented, therefore it is not supported.
ml ml:
> may i kindly ask why the original sender address cant be passed for
> the address_verify_sender feature? Is there a specific reason?
First, software is not like a statue where someone has to remove
material from a block of stone, in order to reveal the artwork that
is already present underneath the surface. Software is more like
painting where someone has to apply material where none is present.
A Postfix feature does not exist until code for it is written.
Second, using the original sender makes recipient address verification
more expensive, as it requires a verification action for every
(original sender, recipient address) combination instead of just
one per recipient address. This multiplication factor can be as
large as a malicious sender wants it to be.
Third, this falsely rejects mail when a remote site does not accept
a "local" envelope sender address from "remote" systems (this happens
when "local" senders are required to use the authenticated submission
service instead of the MX service). Thus, Postfix uses a verify
sender address in its own domain to avoid these false negatives.
Generally, the idea is that one considers "what can go wrong",
besides "would not it be cool if ...". Use your imagination.
Wietse
