HELP i have problem with email sending

[p@ndu]

hi



i have return email in mail everytime this one

Subject:   	Mail delivery failed: returning message to sender
From:   	"Mail Delivery System" <Mailer-Daemon@gator1027.hostgator.com>
Date:   	Tue, November 23, 2010 11:15 pm
To:   *****@gator1027.hostgator.com
Priority:   	Normal
Options:   	View Full Header | View Printable Version  | Download this as a file

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  dbmaster@example.com
    "Sorry, you are sending to/from an address that has been blacklisted"

------ This is a copy of the message, including all the headers. ------

Return-path: <***@gator1027.hostgator.com>
Received: from ***** by gator1027.hostgator.com with local (Exim 4.69)
        (envelope-from <*****@gator1027.hostgator.com>)
        id 1PL7h7-0000Mg-QE
        for dbmaster@example.com; Tue, 23 Nov 2010 23:15:01 -0600
To: dbmaster@example.com
Subject: vBulletin Database Error!
X-PHP-Script:  for 117.255.161.206
From: "dbmaster@example.com" <dbmaster@example.com>
Message-ID: <20101124051501.b25c488f5e97@>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 8bit
X-Priority: 3
X-Mailer: vBulletin Mail via PHP
Date: Tue, 23 Nov 2010 23:15:01 -0600

Database error in vBulletin 4.0.6:

Invalid SQL:
SELECT userid
                                FROM xperience_stats
                                WHERE  points_xperience > 250 AND points_xperience > 10 AND 
                                userid NOT IN(
                                        SELECT userid FROM xperience_achievements_issues WHERE achievementid=18
                                )
                                LIMIT 0,100;

MySQL Error   : MySQL server has gone away
Error Number  : 2006
Request Date  : Tuesday, November 23rd 2010 @ 11:09:26 PM
Error Date    : Tuesday, November 23rd 2010 @ 11:15:01 PM

IP Address    : 117.255.161.206
Username      : Unregistered
Classname     : vB_Database
MySQL Version :

i get daily same mails with same message nearly 20-30 mails daily

i have asked in my hosting support they told me that its in vbulletin only so plaes some one help me with this

thank you