Tired of Spam? We'll Help You Install A Spam Filter

Follow these handy steps to a spam-free inbox

Million-dollar scams, innuendos of sexual dysfunction, and cheap drugs from offshore suppliers just don't get us as excited as the authors of this rubbish think it should. Aside from polluting your inbox with all sorts of unmentionables, spam costs you money to receive, it's frequently obscene, degrading, and, in some cases, illegal.

It's time to stop the flood, but where do you start? The most effective way to reduce your spam intake is to install server-side or client side antispam software. Or better yet, both. We'll walk you through the steps to install and configure free antispam software.

Server-Side vs. Client-Side Antispam Solutions

Internet Service Providers ( ISPs) and network administrators typically use server-side software to block spam. Server-side software resides on the mail server and filters messages as they arrive. The software will typically mark mail as potential spam prior to a user downloading it, or delete the message entirely. This whole process is usually invisible to the end user.

Client-side antispam software, on the other hand, resides on your home or business desktop and is used in conjunction with your e-mail client to filter spam. Client-side systems don't block spam on the server level, however these systems can be effective at isolating spam from legitimate messages, making inbox management a much easier task.

The best defense is to combine server-side and client filtering as part of your overall antispam strategy. Luckily, there are a number of products that that do the job, whether you've got just a single home computer or network servers providing e-mail filtering to hundreds of client computers. Low-cost options such as Mailshell or Norton Internet Security (a suite of applications that includes antispam software) are available to nonprofits from TechSoup Stock's catalog for a small administrative fee.

Plenty of free spam filters are available as well. Rather than cover installation and upkeep of several products, we're keeping things simple by covering the installation and use of just one: the Mercury Mail Server by Pegasus, which is free and available for Windows and Novell computers.

Setting Up Mercury as a POP3 Antispam Filter

The steps laid out below will help you set up Mercury as a personal antispam filtering system for your home or business POP3 e-mail accounts.

1. First, download the Mercury Mail Server (the current version listed on the site is, "Mercury Mail Transport System for Win32 and NetWare Systems v4.01a") at Pegasus Mail .
2. Double-Click the Mercury install file you just downloaded.
3. Click "Setup" when prompted (you will need administrative rights on your computer).
4. Select "New Installation."
5. Click "No Netware Support."
6. Select the folder where you'd like the program to be installed.
7. Click "No Pegasus Mail Integration." (Unless you use the Pegasus mail client. In that case, click, "OK. Accept this directory"). If not, accept the directory on the next screen.
8. Tick "Mercury P" (POP3 Server Module) and "Mercury D" (POP3 Client Module).
9. Click "OK Continue Installation."
10. Click "Install No SMTP Client."
11. Type the domain of your ISP (for example, myisp.com) in the box "This Machine's Internet Domain Name." Type "postmaster" as the postmaster username. Click "OK Continue Installation."
12. Click "Strict" for relay control, click "OK Continue Installation" for the Mail queue window.
13. Click "Install Mercury 32," and then click "Exit" when you see the "Installation Complete" window.

Configure Your Mail Server to Filter Spam

1. Start Mercury. The program will start with three small windows displayed in a larger window. (To organize the windows, click the menu "Window" and select "Tile.")
2. Click "Configuration" from the menu and select "Manage Local Users." Click "Add" and enter your ISP username in the username field (this is the part of your e-mail address before the '@' symbol). Enter your real name and the password you use for e-mail (leave "APOP Secret" blank). Click "OK."
3. Click "Add" again to create an account for your spam messages. (Just call this account spam and make up an appropriate password.) Click "OK" and "Close."
4. Click "Configuration" from the top menu and select "MercuryD POP3 Client."
5. Click "Add" and enter the connection details for your ISP (these settings are the same as those used by your e-mail client). Leave the fields "Local User," "Default User," and "Headers" blank. Click "OK" and "Save".

Now that you've finished these steps, Mercury will now automatically check your e-mail and move any spam identified by the preset antispam rules to the "spam" account. We're almost done.

Configure Your E-mail Client(s) to Use Mercury

1. Open your e-mail client. (We'll use Microsoft Outlook 2000 for this example, however the process is similar for most e-mail clients.)
2. Click "Tools," "Accounts," "Properties." In the box called "Incoming Mail (POP3)" delete your ISP's setting (probably something like: mail.myisp.com) and in its place enter: 127.0.0.1 (this is an IP address that points to your computer). Click "Next" and "Finished".
3. Close and restart Outlook. Make sure Mercury is also running and click "Send and Receive" to make sure everything is working properly. (If you receive errors, make sure you've followed these steps and entered the correct information.)
4. Create a folder in your e-mail client called "spam". Click "Tools", "Accounts", "Add," "Mail," and follow the prompts to create an account called "spam" that moves any mail received to the spam folder. Make sure you enter the same password you used for the spam account in Mercury and also set the Outgoing Mail Server (SMTP) for this account to 127.0.0.1 (this is a trick used to prevent spam containing Trojans or worms from using the spam account to redistribute themselves. Because you haven't configured Mercury to act as an outgoing mail server, any mail sent through the spam account will automatically generate an error making you aware of the infection).

If you've followed these steps Mercury is now acting as a POP3 antispam filter for all of your inbound mail. Network administrators can use Mercury as an antispam gateway and mail server by installing the Mercury S SMTP Server and Mercury E SMTP Client. The steps to migrate Mercury from a home antispam system to a corporate system are very easy to follow (everything you need to know is contained in Mercury "Help").

Now that you have installed and configured Mercury, here are a few things you might like to experiment with: familiarize yourself with the Content Control rules used by Mercury ("Configuration" menu, "Content Control"). From here, you can create your own filters or definitions of the content you'd like to designate as spam. Don't be afraid to experiment with these settings (you can always reload Mercury if you make a catastrophic mistake!). For more help, visit this Web page .

If you administer a network or are just interested in running your own full-fledged antispam network mail server, you can implement Mercury's very powerful SMTP and IMAP server features (available by selecting "Configuration" and "Protocol Modules" from the Mercury menu). Everything you need is free and provided with the Mercury install program.

Lastly, be sure to ask for help if you need it. A number of our TechSoup experts use Mercury (just visit our forums to get help). And, typing a query into Google will turn-up a wealth of useful resources (search for "Pegasus Mercury Mail").