======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.5-1
- Linux/BSD distribution name and version: Ubuntu 14.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx):Apache
- Manage mail accounts with iRedAdmin-Pro? No
- Related log if you're reporting an issue:
====
Hi all,
I install iredmail with first domain :abc.com
i want to send email from terminal follow command :
echo "content" | mail -s "subject" -a from:user1@abc.com user2@abc.com
it's okey.user2 can received email from user1 but dont have Dkim signature.
This is header email :

Return-Path: <user1@abc.com>
Delivered-To: user2@abc.com
Received: from mail.abc.com (localhost [127.0.0.1])
    by mail.abc.com (Postfix) with ESMTP id 6738EC23F4
    for <user2@abc.com>; Wed, 16 Nov 2016 20:30:14 +0700 (ICT)
X-Virus-Scanned: Debian amavisd-new at mail.abc.com
X-Spam-Flag: NO
X-Spam-Score: 3.101
X-Spam-Level: ***
X-Spam-Status: No, score=3.101 tagged_above=2 required=6.31
    tests=[HTML_MESSAGE=0.001, MIME_HEADER_CTYPE_ONLY=1.996,
    MIME_HTML_ONLY=1.105, NO_RELAYS=-0.001]
    autolearn=no autolearn_force=no
Received: from mail.abc.com ([127.0.0.1])
    by mail.abc.com (mail.abc.com [127.0.0.1]) (amavisd-new, port 10024)
    with ESMTP id hH4oODrgo-rA for <user2@abc.com>;
    Wed, 16 Nov 2016 20:29:59 +0700 (ICT)
Received: by mail.abc.com (Postfix, from userid 0)
    id 2BC50C23F2; Wed, 16 Nov 2016 20:29:59 +0700 (ICT)
Subject: subject
from: user1@abc.com
Content-Type: text/html
To: <user2@abc.com>
X-Mailer: mail (GNU Mailutils 2.99.98)
Message-Id: <20161116132959.2BC50C23F2@mail.abc.com>
Date: Wed, 16 Nov 2016 20:29:59 +0700 (ICT)

So how can i send email from terminal and header email have dkim signature ?