Installing Spam Assassin POP3 Proxy for Windows will provide the basic functionality for creating an excellent filtering system for SPAM emails under Windows. Better again, Spam Assassin POP3 Proxy or 'saproxy' is completely free. The user should be aware of a number of limitations before an installtion is attempted. Spam Assassin Proxy like all SPAM filters is not 100% accurate. This is due to the fact that while all SPAM filters rapidly adapt their detection methods to changing SPAM, SPAMers are working very hard to disguise their SPAM emails as legitimate emails. Due to this, on occasion SPAM emails will still make it through to your email box. Likewise, on occasion legimate emails may be mistakenly filtered out as SPAM. Some options within SAproxy, such as DNSBL (Domain Name Server Black List) will improve the accuracy of your SPAM filter, but will slow down the delivery of the emails, due to each email being checked against a 'Black List' of mail servers.
A word of warning before we begin. A basic undering of configuring email accounts will be required. There will be a need to manually modify your email program's settings to work with the proxy to achieve filtering. If you're not comfortable getting into the nuts and bolts of the account settings, I would suggest not trying this installation. If any steps do not go to plan, there is a very real chance you will not be able to receive email at all.
Now for a quick explaination of how the filtering will work. In a non-filtered POP3 email setup, the general run of things goes like this. People have your email address. They type up an email addressed to you and click SEND. After a series of events, the new email arrives at a specially configured computer out on the internet called an email server. In this case, it is a POP3 email server. This new email will sit on the email server along with any other email addressed to you, until it receives some instructions from you to do something with it. Fortunately you don't need to know the special commands to send to the email server to retrieve the messages, as your email program (Outlook Express, Thunderbird, Outlook, Windows Mail, Eudora and many more) does this for you. Your email program does however need to know a few basic things to be able to log into the email server and pick up your email. At a bare minimum, your email program will need to know the name of your email server(aka the incoming mail server). Something like pop3.corlit.com or mail.bigpond.com. Your email program will also need to know a username and password to log onto your account on the email server and subsequently request any waiting email. Your email program and the email server then go through the motions of transferring the waiting mail over to your email program.
Sadly amongst the valid emails sitting on the email server waiting for collection, is most often the large chunk of unwanted spam emails. Naturally your email program (aka email client) will do nothing on its own to sort the spam from the valid emails. To do this you need something in between the email server and the email client. This is where the email proxy comes in. Once the email proxy is in place, your email client will not request the mail directly from the email server. Instead the email client will request the email from the email proxy. The email proxy will then request the email from the email server. As the email is delivered to the email proxy, it is then checked to see if it is valid mail or SPAM. If an email message is deemed spam, the email proxy will change the subject line of the email to list the message as SPAM.
Your email client will next receive the email from the email proxy. Within virtually all email clients (Outlook, Outlook Express, Thunderbird, etc) is a method to sort incoming mail that may contain a certain piece to text, in this case the '*****SPAM*****' tag added to the subject line by saproxy. Once saproxy is installed on your computer, please select 'The Manual' option from the saproxy group on your Windows Start Menu for a detailed configuration of various email clients. From the main menu which first appears when the manual is opened, select 'Configuring mail clients'. If your email client is not listed in the the manual, reviewing the setup for other email clients listed in the manual is a good place to start to guide you through the configuration process.
This Help File is currently incomplete and shall continue to be modified shortly. This page was last modified on 14th February 2011.
Download SpamAssassin POP3 Proxy for Win32 (Filename: SAwin32-3.2.3.3.zip) from the sourceforge website.