Thread: How to get rid of Spam

What Makes Spam Tick?
Of course, the rise of spam traffic on the Internet has not gone unnoticed by Internet service providers. Many ISP's have instituted some form of spam filtering technology between their customers and the Internet to delete the most obvious forms of spam. These measures are of varying effectiveness, but do help reduce some of the background noise. It's advisable to check up with your ISP to see if they have some form of spam filter working.

In addition, many home Internet Service providers include provisions against sending spam as part of their fair-use agreements for the service. Of course, this is at the discretion of the company, but it is in the interests of a home service provider not to have its members bombarding each other with spam.

Because of this, whole companies are in the business of supplying email services to would-be spam merchants. They provide the Internet access and email servers and the spammer provides the content.

The idea of a national do-not-spam list has been proposed in the United States, but has never really gotten off the ground. This is mainly due to a host of reservations as to how it will affect legitimate online businesses, and the (probably very real) fear that a national list of valid email addresses will simply attract more spam. The latter point illustrates the main problem with legal action vs. spam email senders.

The required operating costs are so low for sending out spam that the people who do it are under no real pressure to operate their businesses legally. This is different from the spammer's closest analog, telemarketing companies. While equally annoying, they need employees and expensive phone lines and equipment to function, meaning they must run a (at least semi-) legitimate business and a national do-not-call list would be effective. No such insurance exits with spammers, and a national do-not-spam list would almost certainly be abused.

How did you get on a spammers mailing list?

Most commercial spam emails are sent using huge lists of email addresses, bought or otherwise acquired by the spammers. It's important to remember that your email address (at least your main one) is a commodity on the Internet. This is why so many sites (especially those offering free services such as software downloads or contests) want your email address. If they have your address they can contact you later, and unless they specifically state that they will not, they can also pass the address on so that others can contact you. In the past, many online businesses have sold their customer lists to raise money or during the process of bankruptcy. If you are prompted for an email address and it does not specifically state that your address will not be used for marketing purposes, be wary. You might well become added to a spammers list.

Of course, there are other ways that commercial spammers can harvest your email address. Automated software tools that search through web pages and record any email addresses that they come across are one method, and equivalent tools are also used to pore through newsgroups in search of useable addresses. For this reason, it is advisable not to display your email address when posting within forums.

One of the most common methods, used by many commercial sites and services on the web is the 'opt-in' box, as first seen in those annoying magazine pullout subscription flyers ('YES!! Please sign me up to receive 12 issues of pet taxidermy monthly and send me my free Elvis bust!').

In the Internet age, these take the form of the ubiquitous set of check boxes at the bottom of the sign up page, pre-checked for you of course, and offering "relevant information from time to time," "great offers from our partners," etc. etc. It all adds up to the potential for unsolicited spam if the vendor is unscrupulous and you are careless with your email address.

Techniques to Avoiding Spam
As mentioned earlier, emails triggered by viruses are also a leading source of spam. The most insidious of these may be received directly from people you normally correspond with over email, but the majority are from seemingly random addresses or disguised ones, an example being the recent 'Microsoft patch' worm known as 'W32.Dumaru @ mm' which you may have received in the hundreds over the past few months. This worm disguises itself as being from 'security @ Microsoft.com'

Mass-mailing worms such as w32.Dumaru scan files in your computer as part of the process of infection, and can pull email addresses from many other sources besides your Outlook Express address book. In fact, most recent worms can extract email addresses from stored .html files in your Internet Explorer history folder, meaning any email address on any web page you have visited recently is going to get spammed by you if you unwittingly infect your computer.

Techniques to Avoiding Spam

Let's look at some methods you can use to stem the flow of garbage into your inbox. Several of these are pure common sense, but by applying all of the methods together, you can armour yourself quite effectively against spam. Unfortunately, there is still not really a reliable method for stopping the spam from reaching you altogether without losing the occasional important message, so the below methods focus on filtering spam out to 'junk' folders and addresses so you do not have to pick through it to get at your regular mail, blocking out repeat senders of unwelcome email, and using common sense to avoid common 'spam traps' in the first place.

Junk addresses

One of the best ways of avoiding spam is to not avoid it at all, but to actually welcome it, with open arms into an email address that you have no intention of checking. Make a Hotmail account, or the equivalent (you know, boxospam @ somesite.com) and use this address when you are registering or filling out forms for companies you have no interest in ever receiving email from. Empty the thing out once a month if you like, but otherwise you can happily let the junk mail accumulate in a tidy pile away from your view.

Opt-out of opt-ins

As we stated before, it is highly unlikely that any of the pre-checked offers from whoever you just signed up with are going to offer you anything besides more spam to clutter up your inbox. The sensible thing to do is to uncheck anything you are not sure you want to receive. This will help cut down on your spam quotient.

Note that while many spam emails will offer a link to allow you to remove yourself from their mailing list, this is often not a sensible thing to do. While 'legitimate' commercial email purveyors may respect your wishes on this front, replying to the addresses provided may simply serve to confirm your email address as working and invite more spam. Better to use one of the below methods to block it out completely.


Using Outlook Express message rules to filter spam

Outlook Express contains a simple set of message handling rules that you can put into effect to sort your incoming mail. Depending on the subject, the sender, the contents of the email or its attachments, you can choose to stream email to a separate folder or even delete it automatically.

In effect, OE will examine your incoming mail and decide how to handle it based on the rules you specify. Message rules are useful for filtering out repeating spam like the fake Microsoft patch email, or spam that covers a certain subject (you might wish to block out the V-word for example, or possibly 'add inches...').

How to institute message rules
To apply message rules first open Outlook Express.We need to create a new folder within Outlook Express. Right click on 'local folders' and select 'new folder.' Call the new folder 'spamcan' for now.

Go to 'tools\message rules\mail…' to open the new message rule window.

From here, our first step is to choose the 'condition' the thing(s) that we wish to avoid in our email. Simply check the conditions you wish to apply, then specify the exact details in the 'rule description' pane at the bottom.

For example, if you are receiving spam emails with the subject line 'earn $$$ at home,' check the 'where the subject line contains specific words' box, then click the underlined link in the 'rule description' pane.


In the 'enter specific words' window, type 'earn $$$ at home' and click 'add,' then 'ok.'

Now we need to specify the action to be taken when Outlook Express finds an email with the condition(s) you specified. As you can see, there are a number of options, including deleting the offending emails automatically. Be cautious with the delete option though, since you could end up destroying useful mail. This is why we created a 'spam' folder so we can funnel our useless messages there to be checked one or twice a month.

Filtering with Message Rules
To continue the example, say we want all messages with 'earn $$$ at home' in the subject line to be placed in the 'spamcan' folder we created. Check the 'move it to the specified folder' box, then in the 'rule description' pane, click the underlined link and specify the 'spamcan' folder as the target.


Now our rule is complete. Give it a name and click 'ok' to apply it to all future mail.

This is one example of how message rules can be useful, but I've found that when the message rules begin to pile up, they don't always work 100%. Other good uses are to funnel all email containing attachments into a separate folder where they can be handled with care, or even just organizing your mail by funneling messages from specific people to specific folders. There are more effective ways of organizing your email though, and we will look at one example of this later in the article when we combine message rules with a third party sorting program to try and block spam more proactively.

Blocking spam with Outlook Express

You can also use the message rules menu in Outlook Express to easily block mail from a specific address. This function (the 'blocked senders' list) automatically funnels all mail from these sources into the deleted mail folder. To set an address to be blocked:

Open Outlook Express, go to 'tools\message rules\blocked senders list'.


Click 'add' then type in the address you wish to block. Click 'ok.' That's it.

Spam Blocking/Filtering Software
There are many, many commercial and freeware spam blocking software packages available. spam blocking is a common concern, especially for businesses that run their own servers and are seeing precious bandwidth and storage space eaten up by awaiting unsolicited commercial email. For this reason, many high profile software companies like Symantec have weighed in with commercial spam blocking solutions.

Generally these software packages will give you the option to delete spam outright or funnel it into a 'junk' mail folder. To identify spam, they use one of three methods: Blocking spam by examining the contents of the email for words and combinations of words that indicate spam, blocking spam by using an updateable list of known spam senders or blocking all email that does not come from approved sources ('whitelisting').

The major issue with all spam-blocking software is false positives. In an ideal world, your software would delete all spam before it even got to your inbox, and many current programs are capable of doing just that. The trouble is, they will also inevitably munch some email that you actually wanted to receive. The solution to this, as it seems to be with all methods of spam filtering, is to funnel the suspected spam into a separate folder where it can be checked occasionally without interfering with workflow.

While there are too many spam-fighting programs available for us to give how-to's on each one, most offer free trial periods so you can get a sense of how they will work with your computer. Also some free web browser alternatives to Internet Explorer (like Mozilla) offer built in spam filtering that is a bit more robust than the options included with Outlook Express.

Some examples of commercial antispam software include:

Norton Antispam 2004

Stata Lab's Saproxy Pro

Giant's spam Inspector 4

And Freeware antispam software:

Extravalent's POPFile

Using POPFile and Outlook Express message rules to filter out spam email

As POPFile is one of the more popular and mature open source mail filtering software packages, we thought we'd give a quick tutorial on setting it up to sort your mail. Note that this tutorial is not intended to replace reading the POPFile manual, and we recommend you do that as well.

POPFile works by analyzing your mail before it reaches your mailbox, then assigning it to a category (bucket) depending on the contents of the message. It needs to be taught by the user to recognize what is or is not spam at first, but it will 'learn' from the choices you make and gradually become more efficient and independent.

Note that while POPFile can be set to quarantine certain messages, it will not otherwise interfere with the email reaching your client. It is a sorting program only, so it is good if you are signed up to several newsletters which might otherwise stop being received if they have to be manually authenticated. If you want something specific done with the email than POPFile classifies as spam, for example, you will have to create message rules to do this. Fortunately, POPFile can attach 'tags' to the subject line of suspect emails so it is easy to sort them out. Let's take a look at how to do all this

Working with POPfile
For the purposes of this demonstration, we will be creating a new folder in Outlook Express (or any other mail client, providing it supports creating message rules) called 'spam' then creating a message rule to ensure that anything POPFile classifies as spam is sent to the spam folder and not the inbox.

Open Outlook Express and create a new folder called 'spamcan' by right clicking on 'local folders' and selecting 'new folder.'

Now go to 'tools\message rules\mail' and create a new message rule with the condition 'where the subject line contains certain words' and the action 'move it to the specified folder.' The subject line setting should be

[spam] And the folder is spamcan

Now download and install the 0.20 version of POPFile from Extravalent's website.

You will be prompted to create 'buckets' during the install process. A bucket is a category that POPFile uses to classify incoming email based on its contents. You should create the 'spam' bucket and at least one more, depending on whether or not you wish POPFile to filter your regular email into separate categories. The more buckets you create, the longer it takes to train POPFile correctly.

Once POPFile is installed, have it run in the background. Double click on the octopus icon to bring up the POPFile interface. POPFile will begin filtering your email. Note that until you begin teaching the program what emails constitute spam, it will not attempt to actually sort at all, but simply pass all mail through to Outlook Express.

The history tab is where you do your teaching. POPFile will record all mail from the last few days here. As soon as you receive mail, go to this screen and reclassify the mail into one of your 'buckets' using the drop-down box and the 'reclassify' button. The program will take note of the contents of the email and how you classified it and use this knowledge to begin the sorting process. It will now attempt to sort all subsequent messages based on this new knowledge.

When POPFile sorts email, it adds the bucket name to the subject line of the email, so a spam message with the subject 'make $$$ fast' would appear as '[spam] make $$$ fast' in your inbox. Because of the message rule you created, this email would promptly be dumped in the spamcan folder.

For the first little while, POPFile is going to incorrectly sort a LOT of messages. Be prepared to keep teaching it by using the 'reclassify' button and the drop down boxes in the history tab. The more email it sorts, the better it will get, until your assistance is no longer necessary. The 'buckets' tab shows the current success percentage of the program.

POPFile has a few other features which you can find through the manual and attendant forums (the links are at the bottom of the interface page). After using this combination for a week or two, you should find that your spam problems are ironing themselves out nicely.

After using the POPFile method with Outlook Express, as detailed above, 80% of 185 emails have been correctly identified over 2 weeks, starting from scratch. In the last 5 days, accuracy has been more like 90% as POPFile learns what is [spam] and what isn't.

[Update:] After about two months of using POPfile we've come to find it isn't really able to handle email accounts that get lots of mail, as in 1000+ emails a day. With all the correspondence for PCstats, Viruses, and Spam that the half-dozen email address I use get, I've found POPfile tends to crash after about 1500-2000+ emails have been processed in one or two days. This is especially the case if you forget to clean out the list of messages that POPfile uses for categorizing, and is usually indicative of a really long wait getting into the POPfile UI where this is done.

Sadly, while I will miss POPFile sorting out all the Spam I get from the Work emails that come in, I'm going to try another option that can handle a couple thousand emails every few days. POPfile worked really well at sorting through the messages - and in fact achieved 90-95% accuracy, but I think it is better suited to slightly lower email volume than I'm blessed with. Now, for the rest of you - please do us all a favor and update your virus protection software. Do your part to stop the spread of Virusmail.