==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.8
- Linux/BSD distribution name and version: centos 6.5
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):roundquebe
- Manage mail accounts with iRedAdmin-Pro? no
- Related log if you're reporting an issue:
====
This is the mail system at host mail.example.com.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<mamun.388@gmail.com>: host gmail-smtp-in.l.google.com[74.125.68.26] said:
    550-5.7.1 [182.16.158.124      12] Our system has detected that this
    message is 550-5.7.1 likely unsolicited mail. To reduce the amount of spam
    sent to Gmail, 550-5.7.1 this message has been blocked. Please visit
    550-5.7.1  https://support.google.com/mail/?p=Unso … ssageError 550
    5.7.1  for more information. n5si10608334pgh.152 - gsmtp (in reply to end
    of DATA command)
Reporting-MTA: dns; mail.exampl.com
X-Postfix-Queue-ID: 9032813A905E
X-Postfix-Sender: rfc822; mazbah@example.com
Arrival-Date: Wed, 23 Nov 2016 14:53:30 +0600 (BDT)

Final-Recipient: rfc822; mamun.388@gmail.com
Original-Recipient: rfc822;mamun.388@gmail.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; gmail-smtp-in.l.google.com
Diagnostic-Code: smtp; 550-5.7.1 [182.16.158.124      12] Our system has
    detected that this message is 550-5.7.1 likely unsolicited mail. To reduce
    the amount of spam sent to Gmail, 550-5.7.1 this message has been blocked.
    Please visit 550-5.7.1
    https://support.google.com/mail/?p=Unso … ssageError 550 5.7.1  for
    more information. n5si10608334pgh.152 - gsmtp
Received: from localhost (unknown [127.0.0.1])
    by mail.example.com (Postfix) with ESMTP id 9032813A905E
    for <mamun.388@gmail.com>; Wed, 23 Nov 2016 14:53:30 +0600 (BDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=example.com; h=
    user-agent:message-id:references:in-reply-to:subject:subject:to
    :from:from:date:date:content-transfer-encoding:content-type
    :content-type:mime-version; s=dkim; t=1479891210; x=1480755210;
     bh=ecWAkWRFSQ0A9Ukr7axD+gjgTrub5MuW4t7HV7IzgYU=; b=W5/gbY6+9DT6
    IlpOYMtC6qID8kOJEDWWU/DKAH3fQGypY4hVBzusPTmB0Yu4gjb7njjUFWfPmOm+
    LAnF1vRZPzMqZn5kvfMOb/yeKoWcaczmuL8clbQBpf5ciuM3vnR6hqDcv6cSqmaH
    znmbBa7/HOWoIn8nEDetXSOgftKcwus=
X-Virus-Scanned: amavisd-new at mail.example.com
Received: from mail.example.com ([127.0.0.1])
    by localhost (mail.example.com [127.0.0.1]) (amavisd-new, port 10024)
    with ESMTP id laToWSFlOV0K for <mamun.388@gmail.com>;
    Wed, 23 Nov 2016 14:53:30 +0600 (BDT)
Received: from mail.example.com (unknown [127.0.0.1])
    by mail.example.com (Postfix) with ESMTPA id E54E413A8F4D
    for <mamun.388@gmail.com>; Wed, 23 Nov 2016 14:53:29 +0600 (BDT)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8;
format=flowed
Content-Transfer-Encoding: 8bit