How can I Block Spam?

How do I Block Spam?

To date, legal measures have failed to stop Spam.  The primary reason is that Spam is basically a human problem.  You can, however, do something about it using some anti-spam software such as that available in our AVG CloudCare offering.  While anti-spam technology is a good thing, it’s not a foolproof system.  Let’s examine why...

Most anti-spam systems use techniques to analyze and inspect email to determine if it’s spam or not.  These profiles can be obtained over the internet or are built using your local email client’s spam system.  Microsoft Outlook, for example.  Basically, the program will read the email and ask, “Does this look like spam to me?” Based upon the rules available to the system, it will assign points to the message and if there are more points than a certain threshold, the message is marked as spam.  At best, this system will flag “most” spam, but it will likely catch some legitimate email too, also known as Ham.

This system is not as reliable as it seems, however.  If you lesson the rules to allow more legitimate mail through, you’ll end up with more Spam in your email box.. and spend more time pressing the <delete> key.  If rules are too strict, you’ll delete legitimate email that you want.  If you get too many “false positives” you’ll end up having to read all of the spam looking for legitimate email anyway… and what savings that that provide?

The biggest disadvantage of this system is that spam continually changes.  In many cases, the rules don’t thus allowing more spam to get to your inbox over time.  Since spammers also have access to the same tools that you do, they continually test and mold their emails to get by the filters.  For example, in the early days most email that contained the word Viagra in it was caught as spam.  Thus, the spammers changed it to V1agra or V!agra.  An additional technique is to make the entire message an image.. which is hard for the anti-spam programs to filter… as they see an image… not the words on the image.

A big advance analysis techniques is Bayesian filters.  Bayesian filters are sets of rules that can be modified over time as a mailbox is managed.  Often telling your mail system that a certain message is Spam will result in the computer analyzing the message and determining which rules to add to the database based upon the message.  Thus, the filters on your computer will ultimately morph to process email based upon your criteria.  The reverse is also true… when you find an email in the Spam folder and you tell you computer that it’s not spam… 

Another technique is Whitelisting and Blacklisting.  These techniques really don’t work well either.  Adding emails you trust to allow all email to flow in from them, is not as safe as it sounds.  Viruses and hackers often gains access to our friends computers and send out email as them.  Thus, we could receive spam or a virus by whitelisting their email address.  The same goes for blacklists as well.  It’s simply not possible to blacklist all of the domains out there that you don’t want to receive email from… remember, there are thousands of new domains going online every day.

This is continual war between the spammers and the anti-spam developers.  While there is no perfect solution, being vigilant and keeping your anti-spam programs up to date and running properly, will help you in this fight against spam.