cannot able to send and receive emails from our company to other comany

Dear All,

recently we have installed Exchange anti-spam in our exchange 2007 server. after the problem starts, we cannot able to send and receive emails from our company to other comany           (for yahoo or hotmail its working fine).

we dont want to uninstall the anti-spam as we are getting lots of spam mails.

when ever we are trying to send an email its giving the below message:-


Diagnostic information for administrators:

Generating server: exchange2007.aayanleasing.loc #550 No RDNS entry for ##

Original message headers:

Received: from exchange2007.aayanleasing.loc ([]) by
 exchange2007.aayanleasing.loc ([]) with mapi; Mon, 1 Mar 2010
 12:24:14 +0300
From: Raed Ahmed Alkhayat <>
To: "" <>
Date: Mon, 1 Mar 2010 12:24:13 +0300
Subject: Quotation Request
Thread-Topic: Quotation Request
Thread-Index: Acq5IIqkt9j/fP6BRmqL8bur4gY8tgAAFcsQ
Message-ID: <514B05B0B698B04EB28F8909BE36B39F1B6350FB09@exchange2007.aayanleasing.loc>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: yes
acceptlanguage: en-US
Content-Type: multipart/related;
MIME-Version: 1.0
Who is Participating?
Go to and do an mxlookup.  You do this by entering your domain name, less the www. in  the dialog box and selecting lookup.  When your result comes back click the option for an smtp test.  The results will tell you if your reverse DNS is set up properly.
The error is saying that the reverse DNS lookup for your mailserver failed. This is a lookup the recipient's server does to be sure the name & IP of the sending server is "legitimate" by seeing if it matches what is in DNS. Be sure the server sending your messages has an MX record that matches the name/IP from which it is sending. If this MX was recently added, it can sometimes take a day or two for it to replicate out into the public.
shariqsaeedAuthor Commented:
Your answer is fantastic. can you show me how can i see MX record (Step by step)
shariqsaeedAuthor Commented:
i have checked MX record . There is no problem with MX record.
 i can able to send to some of the companies & some of the companies  i cannot send an email.
to whom i cannot send out of them one of the person told me that our domain server is not secure.
go badck to the same screen and choose check blacklist.  See if you are on amy blacklists.  Also copy and paste the results of the first test here.  Are you getting any non-delivery receipts when you send the mail?
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