Ralf Hildebrandt:
> * Sabahattin Gucukoglu <m...@sabahattin-gucukoglu.com>:
>
> > Is it a bug or a feature that success DSNs requested for the null sender
> > come to the postmaster?
>
Here's what happens. First, mail to the null address goes to
MAILER-DAEMON by default:
empty_address_recipient (default: MAILER-DAEMON)
The recipient of mail addressed to the null address. Postfix
does not accept such addresses in SMTP commands, but they
may still be created locally as the result of configuration
or software error.
Second, it's common to have an alias MAILER-DAEMON -> postmaster,
so that explains why the mail for <> ends up there.
Postfix sends delivery notifications as mail from <>. When this
first-order notification fails, Postfix will attempt to deliver a
second-order notification to the 2bounce_notice_recipient (default:
postmaster) as a final attempt to avoid loss of mail.
This handling of fail/delay notifications satisfies the RFC's
requirement of never responding to the <> sender address.
However, the code that handles NOTIFY=SUCCESS fails to satisfy that
RFC requirement. It was written several years earlier to implement
support for "sendmail -bv" and "sendmail -v", and was not updated
when it was put into service to also handle SUCCESS notifications.
I'll make the NOTIFY=SUCCESS handling consistent with fail/delay.
Wietse
