Connecting Exchange 2000 to the Internet
One of the most common questions I get asked is “how do I configure my Exchange 2000 Server to collect mail from my ISP?” The answer I normally give is “why do you want to do that?” It is possible to configure Exchange 2000 to collect mail from an ISP but you need to purchase a POP3 connector and they can be expensive and they are not the most reliable things in the world.
Having Exchange 2000 host your company’s Internet mail is not complicated and does not take long to configure. One of the other benefits of hosting your own mail is that you can control it much better.
In this article we are going to look at how to configure your Exchange 2000 Server to host your own Internet based mail.
Here is a check list of the things you will need to start with:
· Good connection to the Internet (DSL, Cable, T1 etc)
You will need to look around your local area and find out what options are available to you for Internet connections; this is probably going to be your biggest expense with getting Exchange connected to the Internet.
· Registered Domain Name
You may already have a registered domain name (such as company.com). If not, visit www.register.com to find one that suits you.
· Public IP Address (static or dynamic)
Whoever provides you with your Internet connection will also provide you with a public IP address. Public IP addresses are unique on the Internet and no two machines will have the same one.
You will get your public IP address in one of two forms: it could be a “static” IP address which means they will actually provide you with the IP address (like 18.104.22.168), or you may get a “dynamic IP” address which means you get an IP address from the providers DHCP Server.
I would strongly recommend trying to get a static IP address if you can; it will make life a little bit easier later on.
OK, so when you have your connection to the Internet (IP address and Domain Name), you now have to fit all the pieces together to get it to work.
Let’s look at how mail is actually delivered over the Internet. The protocol that is used to deliver mail via the Internet is the Simple Mail Transfer Protocol (SMTP). SMTP uses port 25 to communicate.
Let’s say you send a piece of mail to email@example.com. What happen is that the Server that deals with your outgoing SMTP mail says “OK I need to find a server that is capable of dealing with SMTP mail for exchangetrainer.com”; it does not care about the actual recipient.
In order for your outgoing SMTP Server to find a server that processes mail for exchangetrainer.com, it needs to query a DNS Server and it will be looking for an MX (Mail Exchanger) record for exchangetrainer.com.
With me so far? Good!
Given the information I have presented you with above, you are going to need an MX record for your Domain Name. This MUST be created on a public DNS Server. The company that provided you with your Internet connection may offer a DNS hosting service or the company you registered your Domain Name with might be able to do it for you. The MX record refers to a Host Name and there will then be a Host (A) record that links that Host Name to an IP address. For example:
Exchangetrainer.com has an MX record that points to mail.exchangetrainer.com. There will also be an A record that points mail.exchangetrainer.com to a public IP address.
Now, what happens if you have a “Dynamic” IP address? This could get complicated as your IP address is not always going to be the same. I would recommend looking at the service provided by www.dyndns.com, they have the ability to allow you to host your DNS records and point them to a Dynamic IP address.
OK, so you now have your MX record created that points to your public IP address. The next step is to make sure your users have valid SMTP addresses. Microsoft Exchange 2000 uses something called “Recipient Policies” to assign SMTP email addresses to your users.
What you need to do is check to make sure the correct addresses are being assigned.
In Exchange System Manager, expand the “Recipient” container and then click on “Recipient Policies”. On the right hand side of the screen you should see “Default Policy”.
Right click over “Default Policy” and select Properties. The properties dialogue box for the Default Recipient Policy will now be displayed.
Click on the “E-Mail Addresses (Policy)” tab.
If you notice in the dialogue box above, the SMTP address that will be assigned to my users is @exchangetrainer.com - this matches the Domain Name that I have registered. You should ensure that this setting matches the Domain Name you have registered also, if it does not, click on the SMTP rule and click on “Edit”.
When editing your SMTP rule, in the “Address” field you need to enter the Domain Name you have registered. It is important to note that you must include the “@” sign in the name, if you don’t you will encounter many future problems.
Many companies want their users email addresses to be in a particular format, such as
The Recipient Policy has a series of variables that you can use:
%s = Surname (Last Name)
%g = Given Name (First Name)
%i = Middle Initials
%d = Display Name
%m = Exchange Alias
So if you want their email addresses to be in the format of
Now you need to make sure you can send SMTP mail! So, your server needs to be able to find the MX records for other domains on the Internet. This is quite simple to configure.
In Exchange System Manager, locate your SMTP Virtual Server. This is normally located in “Your Server Name” > Protocols > SMTP
Right click over “Default SMTP Virtual Server” and select Properties. The properties dialogue box for your SMTP Virtual Server will now be displayed.
Click on the “Delivery” tab and then click on the “Advanced” button located on the bottom right corner of the dialogue box.
The “Advanced Delivery” dialogue box will be displayed (see below), click on the “Configure” button.
The “Configure” dialogue box is displayed. Here you will need to click on the “Add” button and enter the IP address of a Public DNS Server that you can use to resolve names. Again this information maybe provided by the company who supplied your Internet connection or the company hosting your DNS.
That is pretty much it on the Exchange side of the house, but you may have a few more configuration changes to be made on your network. These changes may relate to things such as your Firewall configuration and/or your Router configuration. As an example my Exchange Server sits behind a Router that connects me to the Internet. My router has my Public IP address assigned to it, so I have configured my Router to forward all SMTP traffic that it receives over to my Exchange Server. The Exchange Server has a Private IP address that is not visible on the Internet. This process is often referred to as “Port Forwarding”, so when my Router receives an SMTP Packet that uses port 25 it forwards that packet of data onto my Exchange Server. The figure below shows the configuration screen from my Router.
Well I hope this article has given you some insight into how easy it is to get your Exchange 2000 Server connected to the Internet whereby it gives you the freedom to move away from ISP hosted mail.
In my next article we are going to look at the configuration options of the SMTP Virtual Server in more detail, we shall also look at the SMTP Connector.