Return_path equal to From

I have PhpSuexec enabled and the headers sent from php mail are like that:

Code:

Return-Path: <user@admin.hostname.com>
Received: from thurs by admin.hostname.com with local (Exim 4.66)
        (envelope-from <thurs@admin.hostname.com>)
        id 1IZj0S-0002n5-Vy
        for email@site.com; Mon, 24 Sep 2007 04:09:07 -0400
To: email@site.com
From: Thurs Admin <support@hostname.com>

admin.hostname.com is the server hostname.

Is it possible to set the Return_path and envelope from to the email listed in From header?

I've tried add 'untrusted_set_sender = *@+local_domains' in the Exim config but that doesn't work.

Please help, this is a common problem for receiving the emails sent by php to aol and yahoo recepients.

My exim config is:

Code:

queue_only_override = false
no_message_logs
log_selector = +arguments +subject
timeout_frozen_after = 4d
ignore_bounce_errors_after = 2d
local_from_check = false
untrusted_set_sender = *@+local_domains