Preventing Spam on your VPS v2

Unsolicited Commercial Email (UCE), also known as Spam, is a growing problem for companies and individual with an internet presence. While legitimate mailing lists of interested customers are useful to a business, a constantly increasing volume of Email messages, often advertising semi-legal or questionable products, are being delivered to thousands of Email addresses.

While the legal definition of UCE varies from one place to another, spam.abuse.net provides a general description on their What Is Spam? page. The following is an excerpt from that page:

Spam is flooding the Internet with many copies of the same message, in an attempt to force the message on people who would not otherwise choose to receive it. Most spam is commercial advertising, often for dubious products, get-rich-quick schemes, or quasi-legal services. Spam costs the sender very little to send -- most of the costs are paid for by the recipient or the carriers rather than by the sender.

In addition to consuming your Virtual Private Server resources, spam can create a load on the network infrastructure that allows your VPS to be accessed by others. For these and other reasons, our AUP specifically bans\ sending spam:

Subscribers violate our policy and the service agreement when they, their customers, affiliates, or subsidiaries engage in spamming. Sending unsolicited bulk and/or commercial messages over the Internet is not only harmful because of its negative impact on consumer attitudes toward us, but also because it can overload our network and disrupt service to our subscribers. Also, maintaining an open SMTP relay is prohibited. When a complaint is received, we have the discretion to determine from all of the evidence whether the E-Mail recipients were from an "opt-in" E-Mail list.

Preventing Spam Relays

Because of the growing anti-spam sentiment among internet service providers, spammers frequently try to use another person's E-mail server to send their messages. Your Virtual Private Server is designed to prevent your server from being used as a relay. SMTP authentication prevents anyone who doesn't have a legitimate E-mail account on your Virtual Private Server from sending E-mail from your server. We also provide NMS Formmail, which prevents spammers from using your Web-based forms to send spam.

Blocking Incoming Spam

There are a number of different tools available to help keep unwanted spam out of your Virtual Private Server Email accounts.

• The acccess file
• The M4 macros
• Procmail - Mail Filtering
• SpamAssassin
• Wpoison - Prevent Address Harvesting

More Information

For more information about spam and resources that can be used to fight it, see the following Web sites:

• CAUCE - Coalition Against Unsolicited Commercial E-Mail
• SpamCop
• UXN Spam Combat
• The SPAM-L FAQ
• Responsible Anti-Spam Sites