Configure DDNS services for  Exchange, SBS 2003/2008, etc.

Often a small business  cannot justify the cost of acquiring a static IP  from their  ISP. It is still possible to host e-mail and other services using a dynamic public IP, but you will need to use a DDNS service (Dynamic Domain Name Service). The following instructions use services offered by  No-IP ( www.no-ip.com see link below), my preference, but similar services are offered by other vendors such as www.dyndns.org .

The following  assumes you have already purchased a domain name from a registrar. There is no need to host it with your DDNS provider but if they support your domain suffix, such as .com, you can transfer it to them for management simplicity if you wish. You can also purchase a domain through most DDNS service providers if you do not already have one. However, for the purpose of this article it is assumed the domain is with another registrar.

Set up DNS records:

I recommend purchasing and configuring the necessary services first, followed by making the changes with your domain registrar so that there is no interruption of service if the domain name is already in use. You will need to open an account with No-IP and then purchase their Plus Managed DNS service ($24.95/year). To locate, on the No-IP menu choose Services,  managed DNS, No-IP Plus, learn more. Then simply enter your public domain name, click "add my domain", and then proceed to check out.

Once complete, you need to configure your DNS records. To access the management screen select "Your No-IP" from the top of the screen,  DNS hosting, then modify next to your domain name.  No-IP sets up assumed common DNS records like ftp.DomainName.com which you can leave, or I would recommend removing and just creating the records you need. Click on "Add a host" .  In the dropdown list to the right of Hostname, select your domain. In the window to the left enter the name you will use to connect to your server. This can be anything you like but if using a certificate, self-signed or purchased, it must match this name. Common names are mail, the name of the server, or the default with Small Business Server 2008 is "remote".  Click the "Create Host" button at the bottom to save.

Next you need to create an MX record for mail delivery. The MX record would usually uses the Host record you just created, but if you plan to use a different Host name you need to repeat the above process for the additional Host record.

Return to the "Managed Hosts" page and click on "Modify" next to DomainName.com (the root).  In the bottom section of the page under mail options enter the Host record you created (not an IP) and click the Update button.

Chances are if you are using a DDNS service you have only one server (one MX record). You may want to consider a backup MX service such as the one offered by No-IP. This is added as a second, lower priority, MX record and in the event your server is off line, the No-IP service stores any mail destined for your server for up to 7 days until your server is back on line.  It then automatically forwards all mail to your server.  One of the nice features of the No-IP Backup MX service over others is it offers an online usage report. Often you may not be aware your server was off-line due to an ISP outage. The Usage report will record when and how long.

If you have other services such as a web page hosted with a 3rd party or at a second site, you need to create another host record for www.DomainName.com pointing to the appropriate IP. If not an IP and you need to redirect to another URL you can use the  "Web Redirect" option.

Configure the DDNS client: