How to verify internet configuration.

Posted on 2006-04-18
Last Modified: 2010-03-19

the situation was, our email was hosted on a third party, that also manage our DNS.

we install on our network a exchange 2003 server. we ask our host to change the DNS to point the mx record directly to our network.

here is the infrastructure :

INTERNET   ---   FIREWALL  ----  EXCHANGE 2003 Front (DMZ) --- FIREWALL ( SAME ) ---  EXCHANGE 2003.

here is what happen, for outside person, we do not receive everything, we receive, we don't receive,
we can send to everybody.

I check the firewall for spaming, it's off.  AntiVirus is off,  In exchange, DNS check is not selected on both server.

what I suspect is that our host did not modify properly the dns and is relaying the message.  

so I whant to verify our DNS over the internet to check for the MX record.

how can I achive that ?

Question by:Martin_Dalpe
    LVL 5

    Accepted Solution

    LVL 4

    Expert Comment

    You can also use NSLOOKUP from the command line to check this.  The easiest thing is to have several people you know who are in geographically disperse areas, and who have different ISPs use NSLOOKUP to determine what they're seeing for your MX record.  If this isn't an option, you can use NSLOOKUP locally and change your default server so that you're using someone else's DNS Server for the lookup...unfortunately, many ISPs are restricting the use of their DNS Servers to clients in their IP Spaces.  There are still a few DNS Servers out there you can just have to do some trial and error to find them.

    Syntax for NSLOOKUP can be found here:

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    Find Ransomware Secrets With All-Source Analysis

    Ransomware has become a major concern for organizations; its prevalence has grown due to past successes achieved by threat actors. While each ransomware variant is different, we’ve seen some common tactics and trends used among the authors of the malware.

    I was recently sitting at a desk at work with one of my colleagues and needed some information on my home computer. He watched as I turned on my home computer, established a remote session into it, got the information I needed and then shut it down …
    Data center, now-a-days, is referred as the home of all the advanced technologies. In-fact, most of the businesses are now establishing their entire organizational structure around the IT capabilities.
    After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
    Here's a very brief overview of the methods PRTG Network Monitor ( offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

    737 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    21 Experts available now in Live!

    Get 1:1 Help Now