Email Server Setup - Installing
(Page 3 of 5 )
When you install your email server, make sure you either have that computer completely firewalled from the Internet, or at the very least make sure none of the normal email server ports are forwarded to it. You want to set up your server separated from the Internet completely, since spammers are always looking for open-relays.
Throughout this article, I will use the CommuniGate email server as an example, however, I will try to make the ideas as general as possible. This article, however, is not meant to be an exhaustive tutorial for CommuniGate in particular; it serves simply as an example for the topics discussed here. If you wish to make use of CommuniGate, it is important that you follow the installation instructions as well as this article, since there are mundane set-up steps that I will skip in favor of covering more general ideas.
After you have downloaded and installed your email software (CommuniGate in this case), you will need to go to the Web administration interface to set up server configuration. This is done by opening a browser on the server console and going to http://localhost:8010/. Once you have logged in to the Web administration window, you can change and modify the settings for the email server. This will allow you to access and configure each different server component.
General Server Configuration
Under the General Configuration group in CommuniGate you should first define what will be considered Client IP addresses. If you are running on a private network behind a firewall or NAT router, you should set this up to include all of you private IP ranges. This defines any computer on your private network as trusted; later, we will configure the SMTP server to allow them to send mail out through your mail server.
However, what if you are off your private network and want to send email through your server, you might ask? Below the Client IP Addresses box, you will see a box for Non-Client IP Addresses. This box tells the server what to do if someone from off your private network wants to connect to the server. To allow you or others from off your private network to send mail out, set this to “Allow Mobile Users to Login” then set the “Process as a Client IP for:” option to some acceptable time, like 10 minutes. When someone from off of your private network tries to send mail through your server, they will now be required to have their email client configured to log them in both for SMTP as well as IMAP or POP access, something that most email clients do allow.
Another sub-section on this page that may be important to you at some point is the Blacklisted IP Addresses. This is a main page for setting up and configuring how certain IP addresses will be banned from sending mail to recipients on your server. First of all, you can define what happens to mail coming from a blacklisted IP, whether it gets rejected outright or if the server simply adds a header to the mail, allowing individual email clients can be set up to ignore mail with that header or store them in a different folder for the user to view and delete if they wish. If email gets rejected, it never sees the light of day on your server and will not be delivered to mailboxes locally at all.
After this, there is the “Blacklisted IP Addresses” text box. This allows you to manually enter your own selections of IP addresses of bad servers. For instance, if you get a ton of spam coming from one or a range of IP addresses, it might be a good idea to blacklist that IP. The next option is to use Blacklisting DNS servers. These are real-time services that maintain lists of known spammer and Open-Relay servers that you probably don’t want to receive mail from. Some examples of public, free services that do this are www.ordb.net and www.dnsrbl.net. You can put the server name for any of these Blacklist servers in the text boxes here to use their listing of bad IP’s so you don’t have to maintain one yourself.
Finally, you can define Whitelist IPs. These are IP addresses from which you never want to block mail. Generally, you want to use this if you always want to get mail from a certain domain or IP address regardless of whether or not it is listed as an open relay. For instance, if you need to get email from work or school even if their servers might be configured wrong, you would want to put those IP addresses or domain names here.
Next: Domain Configuration >>
More Web Hosting How-Tos Articles
More By Michael Swanson
/ 39 
