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Do I Need A Spam Filter?

Spam is a big problem. A huge industry of spam filtering has arisen.

Do I Need A Spam Filter?

This is actually two questions:

  • Should I use the spam filter included in my email program?

  • Should I spend money purchasing a spam filter?

The Problem with Spam Filtering

Whatever technology or product you have, spam filtering has numerous problems which generally makes it counter-productive:

  • It is not perfect, and real messages will be flagged as spam while spam messages will be delivered normally;

  • Quarantined email still needs to be inspected by you before deletion, so your need to look at each message is not removed;

  • You may have to pay extra for it; and

  • You have to install updates and generally keep it maintained — such as building “whitelists”.

It is for these reasons that generally we believe spam filtering is not worth bothering with. At best, you'll still need to examine every spam message to check for legitimate messages; at worst, you'll miss legitimate messages entirely.

Purchasing A Spam Filter

Spam is a problem, but it is not a problem you should spend money trying to solve.

The most efficient method of dealing with spam is to DELETE IT. You should find you only spend a cumulative total of a few minutes a day manually deleting such messages.

Unless you have enormous volumes of spam (hundreds of messages a day), or you have an internal policy directive which requires offensive material to be filtered from employee's mailboxes, spending money on a spam filter is not productive — because it doesn't actually save you any work.

This is in comparison to spending money on anti-virus software, which is imperative. Viruses and spyware are harmful but spam is almost always benign. If you receive a spam message with a malicious payload, your anti-virus system will block it.

Using An Inbuilt Spam Filter

Modern email programs, such as Microsoft Outlook 2003, contain very high quality spam filters. The emails are automatically moved into a Spam or Junk Mail folder which keeps your Inbox clean.

In the case of Outlook 2003, Microsoft issues periodical updates which are easily obtainable via Office Update.

However, this does not release you from manually inspecting the Junk Mail folder to check for legitimate messages. Even the best technology will mistakenly tag real email as spam. It is not safe to completely trust any sort of automated spam filter. Otherwise you will start every sentence with a customer/supplier with the following sentence: “I'm sorry, I didn't receive that critical message, perhaps my spam filter deleted it…

If you already have a spam filter in your existing system, turn it on by all means. But you cannot escape the need to manually check what it finds.

Filtering By Sender Address

Before the appearance of dedicated algorithm-driven spam filters, many email programs provided the ability to filter spam by the sender address.

Do not bother trying this. It does not work. Spammers use random and fake reply addresses.

ISP Filtering

Many Internet Service Providers offer spam filtering. This should be disabled as soon as possible. The problem is that the spam is moved from your normal mailbox so when you download your email, the filtered messages are nowhere to be seen. The intention is to not only keep your Inbox clean but save you from downloading it at all. To inspect any “quarantined” messages, you will typically need to use the web-based email interface to log in to your mailbox, and this is a secondary task which takes time and completely eradicates the productivity gain from not needing to manually delete the spam.

Spam messages are typically quite small so the download time is not a big problem.

Third-Party Filtering

Third-party providers have spam filtering services. The idea is that you redirect your email to them, they filter it, and you download it. This is not a good idea for a number of reasons:

  • It requires routing your email to a third party who cannot necessarily be trusted;

  • It may add several hours of processing time before the email is available for you to be downloaded;

  • It doesn't free you from the need to manually inspect the quarantined email as a secondary task.

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