[Exim] empty sender in autoreply transport and errors_to opt…

Hello people,

I use some (antivirus) software wich SHOULD notify malicious users
with empty sender <>, generated with autoreply transport. Just like
`normal' Exim bounces. The user under which delivery is done is
declared `trusted'.

Every autoreply message is in the form:

=cut
From: AV-DAEMON <>
Subject: Delivery failure: blah blah blah

blah blah blah
=cut

But I see that Return-Path becomes fully-qualified address like this:

Return-Path: <AV-DAEMON@???>

I use errors_to option in this way:

errors_to = \
${if def:header_X-Loop-Prevention: {bounce@???}{$sender_address}}

By that I tell exim to thraw bounces caused by some software to the
desired mailbox <bounce@???>.

I don't want to accept any more bounces caused by my bounces, and I DO
WANT to supply EMPTY Return-Path: AV-DAEMON <>.

Is it possible?

Thank You.

--
Best regards,
 Peter                          mailto:spam4octan@highway.ru