Configure Exchange Email Server Reverse DNS and MX Records Properly

If DNS is setup incorrectly, your mail server will be IP frequency added to the blacklines. Nowadays most e-mail servers have some kind of spam protection, which means that your entire home page will be closed if you need to be logged on a blacklist of spam.

In this article, I will describe how to configure the correct MX and reverse DNS records for your mail server. This article is based on Exchange 2003/2007 server, but each other message server will follow the same rule.

Distributing IP Address

From the very beginning, it's the first thing you need to do to assign a static external IP address to your home mail server's private home. You must apply these rules to your firewall to send SMTP (port 25) and NAT external IP address to server internal address.

Something that many administrators forget to do or check is to set the assigned NAT rule to use the same external IP address that is created inbound to the mail server. If this is not set, backdoor DNS will not match and then your mail server will be logged on a blacklist. If the firewall rules are correctly set up, the IP address listed on this page should be the same IP address that you mapping the internal private IP address of the mail server.

Create MX Entries for Your Email Server

To use this example, below are all information about my mail server to help you understand what you need to do.

External IP:

Email Domain:

You must be a managerial contact for your external DNS provider of your domain name to make these changes. In most cases, this can be done through a control panel online through a DNS provider. Fail to phone or email.

1. The first thing we need to do is create a file to point out the remote IP address that is mapped to your firewall on the mail server. The host A file can be called something but is commonly called "mail". In our example, we will create "" to point to the IP address ""

2. Almost we will create an MX file to point to a newly created directory of our mail server.

Select "add MX file" on your DNS control panel. Make sure that the address is the root domain in our case ""

Add FQDN as a file we have created, which in our case is "".

The lowest asset is most preferred, but in our example we will set priority as 10.

Use NSlookup to check DNS and MX records are applied

It can take up to 48 hours for DNS to increase, but in most cases 12-24 hours. To check our DNS records are used and correct, we can use nslookup.

1. Open CMD prompt and enter nslookup

2. Model Set Type = Mx

3. Enter the domain that is in our case .

In our example, output should read below if proper setup:


Unauthorized answer: MX choice = 10, mail manager = [19659002] address =

Still DNS lines

Reverse DNS is used to confirm that the mail server is the one that says. The recipient mail server will do reverse search to make sure that the IP address of mail A or host in DNS is the same as the IP address in which it is communicated. Only 1 RDNS entry can be present on an IP address.

To do this, you need to contact your service provider to make this post. You will not be able to do this on your DNS control panel without your server hosting your DNS and giving you functionality to add your own RDNS entries.

In our case, we would like to contact our service provider and advise that we would like to create a RDNS entry for our IP address that would also solve .

Verify Backdoor DNS

Again, it may take up to 48 hours for DNS to spread, but most often 12-24 hours. To make sure that RDNS entries have been corrected and corrected, do the following:

1. Open CMD prompt.

2. Type Ping -a (This is the external IP address of the mail server. In our case, we use our external IP address above)

If RDNS is set correctly, the following output is displayed: 19659002] C: User User> ping -a

Pinging [] with 32 data added:

SMTP Banner

Every time the mail server sets a connection to your mail server and displays its SMTP table. This tape must be solved on the internet and the best exercise is to have it as a mailbox / file.

Configure SMTP Tape Exchange 2003

1. Open Exchange System Administrator .

2. Expand your management group ("First Administration Group" by default).

3. Expand Servers .

4. Expand YourServerName .

5. Expand Protector container.

6. Select SMTP container.

7. On the right pane, right click on The default SMTP virtual server (and Or the name you set your SMTP server) and

select Properties .

8. Select the tab Delivery .

9. Click the Advanced button.

10. Under Full Qualified Domain type (A / Host the file you created in DNS for your mail server)

11. Click OK and OK Again to Accept Changes

Configure SMTP Banner Exchange 2007/2010

1. Open the Exchange Control Panel .

2. Select Organization Configuration the container.

3. Select Hub Transport container.

4. To the right, select the Send Connector tab.

5. Right click on your link and select features .

6. On General tab under Set FQDN this interface will … Enter the name of the domain you created. As in our case, is . Click OK .

7. Under Server Settings click the Hub Transport container.

8. Right Window Select Properties Receiving Interface under Get the Interface tab.

9. On General tab under Set FQDN this interface will … Enter the name of the domain you created. As in our case, is . Click OK

To confirm these changes, we can use Telnet to view the output of port 25 to our mail server. Use the following steps to do this:

1. Open CMD prompt

2. Type Telnet 25 .

The output you see should look like this and contain a file of your mail server:

220 Microsoft ESMTP MAIL Service ready for Sunday, February 28, 2

010 17:51: 20 + 0000

If you use a remote server or SPAM filter device like Barracuda, the SMTP table must be configured on this device / server.

Check if your mail server is in junk mail and / or open rate

Great website to use to view your MX records, RDNS, check if your mail server is open and check if you Registered in spam list is . This is a great place and one to keep your favorites.

The following guidelines will be effective and set mail instructions to and from your mail server. The next step is too secure and ensures that your mail server is not open. I will be writing a special article that is dedicated to this in the near future.

Source by Mike S Collins

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