Kris Deugau:
> To my reading of Jason's first message, the widget/appliance/app that's
> generating the original emails is, in and of itself, (mis)using the null
> sender on (some of) its own original messages, because Reasons.
>
> Jason wants to take those messages, and overwrite a correct envelope
> sender address onto them.
In that case, you may be able to get away with
/etc/postfix/main.cf:
smtpd_command_filter = pcre:/etc/postfix/command_filter
/etc/postfix/command_filter:
# Don't lose command parameters.
/^MAIL FROM:<>(.*)/ MAIL FROM:<u...@example.com>$1
http://www.postfix.org/postconf.5.html#smtpd_command_filter
But this changes the sender for real bounces, too. If you need a
be more selective solution, like only do this for specific SMTP
clients, a Milter coukld do it (in Python, Perl, ...).
Wietse
