I have the same problem on Ferdora Linux (Postfix + Dovecot +amavisd-new)
Roundcubemail version 0.3
Postfix version 2.6.5
Amavisd-new version 2.6.4
The message WAS NOT relayed to:
<nomad71st@example.com>:
554 5.6.0 Reject, id=02076-04 - BAD HEADER
This nondelivery report was generated by the program amavisd-new at host
mail.example.ru. Our internal reference code for your message is
02076-04/MaXyz9XpBHPP
INVALID HEADER
Improper use of control character (char 0D hex): X-PHP-Originating-Script:
0:func.inc\r
Return-Path: <nomad71st@example.ru>
From: <nomad71st@example.ru>
Message-ID: <32eab0fe54ee4954007630a5eb246a99@ote.ru>
Subject: Fwd: Undeliverable mail, invalid header section