Hi,
We are using iRedmail-0.6.0 Based on CentOS 5.5 which for RoundCube Webmail. It is back end OpenLDAP.
From the last 15 days, there are no mails are delivering to gmail. But it is ok in yahoo and other mail.
When we send mail to gmail, it shows successfully sent to gmails. but no mail received in gmail.
And when we send mail from gmail to roundcube webmail, that mail is returning message to sender.

If you have any solution please inform me.

If you have any idea, please provide us urgent solution. I am sending bounce mail:

"-------- Original Message --------
Subject: Undelivered Mail Returned to Sender
Date: Tue, 20 Aug 2013 11:26:26 +0600 (BDT)
From: MAILER-DAEMON@mail.bxpress.net (Mail Delivery System)
To: shafiqul@crm.batworld.com

This is the mail system at host mail.bxpress.net.

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

<shafiqul@batworld.com>: host aspmx.l.google.com[74.125.25.27] said: 550-5.7.1
    [182.160.110.250       1] Our system has detected an unusual rate of
    550-5.7.1 unsolicited mail originating from your IP address. To protect our
    550-5.7.1 users from spam, mail sent from your IP address has been blocked.
    550-5.7.1 Please visit http://www.google.com/mail/help/bulk_mail.html to
    review 550 5.7.1 our Bulk Email Senders Guidelines. zo4si10830857pbc.162 -
    gsmtp (in reply to end of DATA command)

----
Reporting-MTA: dns; mail.bxpress.net
X-Postfix-Queue-ID: DDD851C857B
X-Postfix-Sender: rfc822; shafiqul@crm.batworld.com
Arrival-Date: Tue, 20 Aug 2013 11:25:51 +0600 (BDT)

Final-Recipient: rfc822; shafiqul@batworld.com
Original-Recipient: rfc822;shafiqul@batworld.com
Action: failed
Status: 5.7.1
Remote-MTA: dns; aspmx.l.google.com
Diagnostic-Code: smtp; 550-5.7.1 [182.160.110.250       1] Our system has
    detected an unusual rate of 550-5.7.1 unsolicited mail originating from
    your IP address. To protect our 550-5.7.1 users from spam, mail sent from
    your IP address has been blocked. 550-5.7.1 Please visit
    http://www.google.com/mail/help/bulk_mail.html to review 550 5.7.1 our Bulk
    Email Senders Guidelines. zo4si10830857pbc.162 - gsmtp
Received: from localhost (localhost [127.0.0.1])
    by mail.bxpress.net (Postfix) with ESMTP id DDD851C857B
    for <shafiqul@batworld.com>; Tue, 20 Aug 2013 11:25:51 +0600 (BDT)
X-Amavis-Modified: Mail body modified (using disclaimer) - mail.bxpress.net
X-Virus-Scanned: amavisd-new at mail.bxpress.net
Received: from mail.bxpress.net ([127.0.0.1])
    by localhost (mail.bxpress.net [127.0.0.1]) (amavisd-new, port 10024)
    with ESMTP id ul4yQU4Znmj6 for <shafiqul@batworld.com>;
    Tue, 20 Aug 2013 11:25:50 +0600 (BDT)
Received: from webmail.icb.gov.bd (localhost [127.0.0.1])
    by mail.bxpress.net (Postfix) with ESMTPA id D139C1C8427
    for <shafiqul@batworld.com>; Tue, 20 Aug 2013 11:25:50 +0600 (BDT)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8;
format=flowed
Content-Transfer-Encoding: 7bit
Date: Tue, 20 Aug 2013 11:25:50 +0600
From: Shafiqul Islam <shafiqul@crm.batworld.com>
To: Shafiqul Islam <shafiqul@batworld.com>
Subject: 20.08.2013
Message-ID: <318a911fed5f78a2e88196af233b5cf7@crm.batworld.com>
X-Sender: shafiqul@crm.batworld.com
User-Agent: RoundCube WebMail

20.08.2013 20.08.2013 20.08.2013 20.08.2013 20.08.2013 20.08.2013
20.08.2013 20.08.2013 20.08.2013 20.08.2013 20.08.2013 20.08.2013
20.08.2013 20.08.2013 20.08.2013 20.08.2013 20.08.2013"