[Exim] B\Problem with Retiurn-path and autoreply.

Here is my config (a portion):

Transport:

address_reply:
return_path = "mail-bounces@${domain}"
return_path_add
driver = autoreply
file = /var/exim/${local_part}@${domain}-reply
file_expand
to = $sender_address
subject = "${if def:h_Subject: {Re: $h_Subject:}{Webmaster FAQ}}"
from = $local_part
user = exim

and here is my Director:

auto_responder:
require_files = /var/exim/${local_part}@${domain}-reply
no_verify
transport = address_reply
driver = smartuser


However, when I send mail to that address it is autoreplied and the
Return-path is not filled out. Many SMTP hosts are rejecting my
messages because the smtp layer is delivering with MAIL FROM:<> which is
BAD.

Please help...

--
Theo Schlossnagle
Senior Systems Engineer
33131B65/2047/71 F7 95 64 49 76 5D BA 3D 90 B9 9F BE 27 24 E7