On Spam Blockers and
Blacklists
Background
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?
Spam
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.
Countermeasures
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
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.
Summary
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