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The Misconceptions of Spam Filters

By Laurie Rogers
Posted Wednesday, December 8, 2004

Unfortunately there are a lot of people online that all have many misconceptions regarding Spam Filters. Today I'm going to answer some questions that people have asked me about my "Spam column" for DEMC Small Business Ezine regarding them. With regards to spam filters, one can never have enough knowledge, so I do hope that this article will clear up any misconceptions that you may have.

1. Don't spam filters ONLY apply to those who have NOT opted in?

This is indeed a very sad misconception, Spam Filters do affect EVERYONE who sends and receives email in some way or another. Whether you publish a FREE ezine OR a PAID ezine, it does not matter, if it is being sent by email it affects YOU. The biggest problem with filters is that they have NO way to detect that the email message is in fact "Optin", they actually base it on your headers.

Should you use a third party list server, your chances of being filtered are even greater, because of that reason. And this is how ALL filtering is based: By looking at the headers in your email message, by using a point system based on the contents in your subject line as well as the body.

This can also be done by subscribing to a blacklist service that will provide them with a list of domains or hosts that have been identified as being used by spammers -such as (http://www.spamhaus.org) or (http://mail-abuse.org/) AOL, Verizon and Accessus are widely known for using services such as these. It should also be known that spam filtering programs MAY also subscribe to these services, some do and some do not.

2. I heard that spam filters don't apply to autoresponders, is this true?

Actually they do, because if you send email using a third party list server, and put your FROM email address in the field rather than a FROM address on the third party's list server - the spam filter will read it as being a "falsified" email address or header. Because REAL spammers do it all of the time.

3. Spam Filters do not target HTML ezines because they can't read the code properly, is this true?

Yes in fact they do, some more so than text ezines, this is because HTML ezines are considered to be more virus prone. And NOT all list servers and email clients "clean" their email before it is sent. Meaning, even if you do not have a virus on your computer, your ezine can still pick one up during the process of sending through your list server. This has been known to happen on "high traffic" list servers as well as FREE list servers, such as Yahoo Groups.

4. Aren't spam filters ONLY used by large ISP's?

Although it is very true that the majority of larger ISP's use Spam Filters (such as: AOL, Yahoo, Hotmail, Mindspring, Verizon, Accessus, Sympatico etc.) you will find a lot of smaller ISP's use them as well. For instance, my ISP has only 900 customers and they do use them, although I've made it quite clear they are unacceptable on my account. The most "popular program' that ISP's use is called Spam Assassin.

I hope this article has cleared up any misconceptions that you may have had regarding Spam Filters. You can learn more detailed information about Spam filters by visiting: (http://spamassassin.org/tests.html)

Article by Laurie Rogers Copyright 2002 All Rights Reserved

About the Author
Laurie Rogers is co-author of the Ezine Resource Guide, you can check it out at: (http://www.zineadz.com/erg.html) She is the owner of Optin Frenzy a list building program for ezine publishers (http://www.optinfrenzy.com) You can also obtain Laurie's articles at: mailto:ezinearticles@optinfrenzy.com