hello,
I make iredmail server.
when i send mails from roundcube to gmail, all emails send indox, but when I connect my other server to iredmail SMTP all emails send in spam

iredmail server IP: 65.181.123.33
Second Server IP: 65.181.124.233 (which user iredmail SMTP to send mail)

here is original mail header:

Delivered-To: g.nadiradze0094@gmail.com
Received: by 10.216.166.134 with SMTP id g6csp244269wel;
        Thu, 6 Mar 2014 00:46:01 -0800 (PST)
X-Received: by 10.60.58.72 with SMTP id o8mr4493199oeq.23.1394095561090;
        Thu, 06 Mar 2014 00:46:01 -0800 (PST)
Return-Path: <mailer@zegrup2.ml>
Received: from server.zegrup2.ml ([65.181.123.33])
        by mx.google.com with ESMTPS id tk7si4709268obc.146.2014.03.06.00.46.00
        for <g.nadiradze0094@gmail.com>
        (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
        Thu, 06 Mar 2014 00:46:01 -0800 (PST)
Received-SPF: pass (google.com: domain of mailer@zegrup2.ml designates 65.181.123.33 as permitted sender) client-ip=65.181.123.33;
Authentication-Results: mx.google.com;
       spf=pass (google.com: domain of mailer@zegrup2.ml designates 65.181.123.33 as permitted sender) smtp.mail=mailer@zegrup2.ml
Received: from localhost (localhost.localdomain [127.0.0.1])
    by server.zegrup2.ml (Postfix) with ESMTP id 1AC641362E0
    for <g.nadiradze0094@gmail.com>; Thu,  6 Mar 2014 03:46:00 -0500 (EST)
X-Virus-Scanned: amavisd-new at server.zegrup2.ml
Received: from server.zegrup2.ml ([127.0.0.1])
    by localhost (server.zegrup2.ml [127.0.0.1]) (amavisd-new, port 10024)
    with ESMTP id rRL9ML3UPTnk for <g.nadiradze0094@gmail.com>;
    Thu,  6 Mar 2014 03:45:59 -0500 (EST)
Received: from [127.0.0.1] (unknown [65.181.124.233])
    by server.zegrup2.ml (Postfix) with ESMTPSA id 2C1DA1362DD
    for <g.nadiradze0094@gmail.com>; Thu,  6 Mar 2014 03:45:59 -0500 (EST)
Sender: Giorgi Nadiradze <mailer@zegrup2.ml>
Message-ID: <d4d9d0ddd34431df275e3f4b1e7206d3@swift.generated>
Date: Thu, 06 Mar 2014 08:46:02 +0000
Subject: Hello
From: Giorgi Nadiradze <mailer@zegrup2.ml>
Reply-To: Giorgi Nadiradze <g.nadiradze0094@gmail.com>
To: "g.nadiradze0094@gmail.com" <g.nadiradze0094@gmail.com>
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="_=_swift_v4_1394095562_219955c4987bd03e8ce9d37210245a29_=_"
X-Sender: mailer@zegrup2.ml
X-MW-SUBSCRIBER-UID: sz323h7tj98d0
X-Receiver: g.nadiradze0094@gmail.com
X-MW-CAMPAIGN-UID: fo980arg7q046

==== Required information ====
- iRedMail version: 0.8.6
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: Centos 6
- Related log if you're reporting an issue:
====