I hv been receiving fake emails which has fake from address under my domain.
Originating as if from my domain.
And fake dkim signature.
Here below the headers of received email.
My domain is mydomain.com.

My mailserver does not verify X-Original-Helo name with reverse IP lookup.
FAKE: Received: from inbound.efax.com (unknown [46.225.91.79]) 

is there a protection setting at iRedMail ???

====HEADERS OF INCOMING MAIL=============
X-Original-Helo: inbound.efax.com (iRedMail: http://www.iredmail.org/)
Received: from inbound.efax.com (unknown [46.225.91.79])
    by myiredmail.mydomain.com (Postfix) with ESMTP id DDEA4B7E1
    for <me@mydomain.com>; Fri, 23 Nov 2012 18:25:24 +0700 (ICT)
Received: from VOICE.mydomain.com (10.0.0.81) by mydomain.com (10.0.0.191) with Microsoft SMTP Server (TLS) id D4V3OQB8; Fri, 23 Nov 2012 14:55:14 +0330
Received: from VOICEMAIL.mydomain.com (10.95.132.169) by smtp.mydomain.com (10.0.0.67) with Microsoft SMTP Server id XV98LWJJ; Fri, 23 Nov 2012 14:55:14 +0330
===============