You may already know what it is. If so, you probably either love it or hate it. You might use it only because it was turned on by default. You might not know about it because someone turned it off for you and you’ve not seen it since. You might just want me to cut to the chase and introduce the topic for the day so you can decide if you want to invest another five minutes reading the column or move on.

Fair enough. Today, we’re going to talk about the “Preview Pane” or “Reading Pane” found in Microsoft Outlook and Microsoft Outlook Express. When we’re done, you’ll be savvy enough to know whether it’s for you.

If you use Outlook or Outlook Express, the Preview/Reading Pane is usually turned on by default. This means you’ll see a list of all the e-mails in your inbox (and other folders), and then, below or beside that list, you’ll see one of your e-mails displayed. The e-mail that is being displayed is whichever one is currently selected (or highlighted) in the list. The e-mail “previews itself” for you whenever it is selected, and it uses the Preview Pane to do it. It can be argued that this makes it easier to browse through your e-mail. I personally disagree, but that’s just my opinion. Some people like it.

So what? Well, the Preview Pane has a long history of being a bane to computer technicians and network administrators. Many years ago, ne’er-do-wells with nothing better to do created special computer viruses that took advantage of flaws in Outlook and Outlook Express. They loaded e-mails with these viruses that were set to trigger the moment the e-mail was opened. When the e-mail was opened, the payload was delivered, and the user was infected whether he knew it yet or not.

Also, spammers often use a technique where they bury a small image into their junk mail. When you open the junk mail, the image is pulled from a Web server somewhere, and it notifies the spammers that you’re the kind of person who opens junk e-mail. You’ve just become their new best friend.

While users are becoming more cognizant of these types of e-mail threats and have become much more discriminating about the e-mails they will open, the preview pane knows no such limitations.

Imagine this scenario: You clean out your inbox, then go make yourself a cup of coffee. While you’re away, you get an e-mail carrying a brand new strain of virus. Since it’s now the only e-mail in your clean inbox, it is highlighted automatically and displayed in your Preview Pane. At this point, unless you have excellent virus software that is updated and aware of this new threat, your computer will become infected while you’re stirring in the creamer. Not a great situation.

My recommendation to my clients and users for years has been to turn off the Preview Pane. In Outlook Express, click the “View” menu along the top, select “Layout,” then un-check the “Show preview pane” box. If you’re using Outlook 2003 or newer, look for the “Reading Pane” options under the “View” menu, then select the option that turns it off completely. Now, just double-click the e-mails you want to open when you’re ready to read them.

Kevin McDonald: Writer and professional computer/network administrator. He lives in Amarillo with his wife and children, and owns and operates Definition Computers. E-mail Kevin at askthegeek@definitioncomputers.com with questions you’d like to see answered in this column.

(This article was originally published in the Amarillo Independent newspaper.)