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Author Topic: February 2008: On Spam Blockers and Blacklists  (Read 9886 times)
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« on: May 27, 2009, 02:53:46 PM »

On Spam Blockers and Blacklists


As the amount of spam (unwanted solicitous email) increases in your electronic mailbox, associated countermeasures like spam blockers and black lists get more "heavy handed" by the day.  As a result, as spam increases, so does the risk that important/legitimate electronic mail will be blocked or deleted before you ever see it.  Are you sure you are getting all your (valid) emails?  Have you ever had a problem where someone claims to have sent you email, possibly multiple times, but you never get anything from the sender?  It's possible, I would argue likely, that you've been bitten by the tools that you think are protecting you such as a spam blocker or worse: your ISP (Internet Service Provider) blocking certain emails before they ever reach your spam blocker!  How can you reduce spam and still be sure you are getting all your "real" email?  How do you reach a balance between getting so many messages that the real ones get lost in a mountain of junk, versus being protected to such a degree that your protective measures accidentally delete or block messages you actually wanted to see?



After all the "do not call" lists, legislation, and other anti-spam initiatives that have been tried over the last few years, you'd think the spam problem would have gotten better and not worse.  Unfortunately, the problem has grown to a point that many find it difficult to even do business (reliably) via electronic mail.  Of course, part of the problem is that people continue to click on spam and the links within the spam message since there would be no market for spam if no one responded to it!  And of course, many spammers don't follow the law, or worse, exploit it so that they include an "unsubscribe" link in the spam as required by law, but clicking on it does nothing but validate that your email really exists and puts you on even bigger spamming lists!  Bottom line: never respond to spam, never click on "unsubscribe" links unless they relate to services that you know you signed up for, and never, ever click on links within a spam message!

One of the best things you can do is simply not respond to any spam.  If you see a spam that reminds you that you needed to go to a web site, order a product, etc. do not click on any links in the spam message!  Most spam messages contain links that, when you click on them, not only take you to the web page in question, but also credit the spammer with having a successful hit at the same time which is how many spammers get paid.  So if you see something that you absolutely must check out, don't follow the link in the spam message.  Just open your browser and go to the site manually or even better, Google the name of the company or web site and go to the site from the Google results.  This keeps the spammer from getting his/her money because there is no reference telling the company how you got there!  Using Google has an added benefit too, because you might not only get results for the product/company you are looking for, but you might also see that Google brings up a lot of reports about "rip offs", "don't use this company", or other indications that the web site you are about to visit is actually fraudulent or otherwise not a good place to do business.



Of course, we all know what spam is and many of us use some sort of counter measures to keep spam out of our mail boxes.  The most common form of anti-spam is a spam blocker.  Spam blockers are usually just software packages that analyze your email as it comes in to your mailbox so that spam can be detected and either put into a "junk" box or deleted entirely.  Many programs exists that allow you to block spam and I won't go into which ones work better/worse since the point of this article is not how well they work, but that they all have flaws and will occasionally misidentify good email as spam!  Let's take a look at the two major categories of spam blocking tools:

User installed

The first category of spam blocking tools are those that are installed by you, the user.  These can range from virus scanning tools that double as spam blockers or email programs (or email program add-ons) that block spam inside your email program.  On the plus side, these tools are almost always user configurable and allow you to set the strength of the spam filter from low (very few emails will be improperly identified as spam) to high (where more spams might be caught but a significant number of good emails might be improperly flagged as spam).  These tools also usually offer the ability to either move the spam to a spam/junk folder or just delete it so that you never see it.  The biggest problem occurs when users set their spam strength/sensitivity too high and choose to delete mail identified as spam.  In these cases, a fair number of legitimate emails might be improperly flagged as spam and you'll have no opportunity to see those emails or correct the problem because the spam blocker deleted the messages in question.  So lesson one in using a spam blocking tool is to set your sensitivity so that only the most obvious spam messages are marked as spam and also choose to move the spams to a folder rather than delete them.  Doing this allows you to get a handle on how effective your spam filter really is and whether or not it is marking good messages as spam.  As soon as you choose the "delete" option, you are giving your spam blocking tool the authority to "vaporize" your email and that leaves you with very few options.  It's always best to start on the safe side to gain experience with the tools, and then increase their spam detection "strength" only when appropriate, i.e. when you have more experience with the tools and their effectiveness.

ISP installed

The second category of spam blocking tools are tools that are available to you through your Internet Service Provider (ISP).  Some providers offer web based spam blocking tools that you can access/tweak online.  Often these tools are described and supported via the web site of your ISP, and you may need your ISP's help to configure them.  If you have a "generic" email address like Hotmail or Yahoo, you may have access to your mail box via both a web page and your email program that resides on your computer.  When this is the case, it is often necessary to log onto the web site to view the contents of the "junk" folder, especially in cases where you are expecting mail but have yet to receive it.  If you use one of the free online email services and you are missing mail, the first place to look is in the "junk" folder found on the web site since those messages may never make it to your computer and your email program.  In addition to these user-configurable spam blocking/filtering tools, your ISP may use measures outside your control.  See "blacklisting" below for more details.



Blacklisting is a third spam countermeasure that is so prevalent and so counterproductive that it deserves its own separate category!  Many ISP's use one of many online blacklists of (usually) IP addresses that they believe are operated by spammers.  If email is sent to you from one of these IP addresses (or sometimes just one that is close to it), your Internet Service Provider may block the email before it can ever be downloaded to your computer.  In all cases, this amounts to your ISP making the decision for you as to what is or is not spam since you have no control over this type of blocking.  This type of unilateral decision making is by far, the most destructive form of spam blocking because you have no control over it and it often results in legitimate emails being deleted entirely, as if they had never been sent.  Many times, a range of IP addresses are blocked for no reason other than the fact that a lot of outgoing mail is coming from those addresses.  So legitimate emails that are sent to (for example) customers from a particular company might be blocked due to your ISP deciding that it has seen too many emails from a particular IP address when in fact, the emails might be legitimate correspondence between a company and its customers or paid subscribers!  In addition, many spammers use mail "spoofing" where semi-random IP addresses are added to the header so you may find yourself on one of these blacklists just because some spammer decided to forge your IP address into the header!  The more correspondence you do over email, the more likely you'll be to fall victim to spoofing.

If you find that your messages are not being delivered to others and you suspect that you are on some online blacklist, your recipients may suggest that you take steps to remove yourself from the online blacklists.  Don't do it!  Instead, tell your recipients that you sent the email and their ISP is blocking it due to an error on their blacklist(s) and insist that their ISP deliver mail properly!  Put the onus where it belongs: on the people that are deleting your mail for no reason!  If you scramble to remove yourself from errant blacklists, you become part of the problem since those utilizing the blacklists should be held responsible for them working properly.  If you happen to be on the receiving end and you talk to someone who insists they have sent you mail numerous times yet you never get anything from them and you know your own spam blocking tools aren't the culprit, your ISP might be blocking the message(s) due to using a blacklist that has errors.  The onus is on you to inform your ISP that you will not tolerate them only delivering some of your email and deciding not to deliver others without your knowledge!  You pay your ISP (usually) for service and if they are not delivering all of your email, they are not serving you appropriately!  Spam blocking and decisions about spam are things that should be handled by the user, not unilaterally decided by an ISP working with tools that obviously do not work properly.

To make a long story short, if you suspect that your ISP is blocking email to you, they may be utilizing a blacklist that decided what to deliver and what not to deliver to you.  To know whether or not this is happening for sure, you may need to temporarily disable any user installed or online/web based spam blocking so that you can be sure your own tools are not the culprit.  If, after disabling all spam blockers for which you have control, you still don't get all your email, inquire with your ISP to see whether or not they use blacklists to block email before it ever gets to you.  If so, lobby them to stop using such (frequently errant) processes as you don't want them deciding which emails you do and do not receive.  Doing this will force ISP's to solve their own problems (like mail server overload) in other ways rather than pushing their own problems onto you, the people they should be supporting.



Spam blocking and blacklisting has become as much if not more of a problem than the spam they aim to protect you from!  If you utilize spam blocking tools, be sure you know how to use them appropriately or you'll risk losing important emails along with the spam you are fighting.  In addition, be aware that there is another level of spam blocking that happens "behind the scenes" for which most people are not aware.  Your ISP may be taking measures to block spam (spam blocking or blacklisting) and sometimes those measures can block legitimate mails as well.  Unfortunately, you have no control over this latter category except to demand that your ISP deliver all your mail and let you (or your own installed and configured spam blocking/filtering software) decide what is or is not spam.  If we all stop clicking on links in spam emails and we all demand that our ISP's deliver all of our email, the growing problem of not being able to reliably communicate via email would be over.  Sounds easy, right?  I guess, so does world peace... on paper.  ;-)  We are, after all, human.


Mike Chaney

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