It's hard to imagine what life was like before e-mail. It's fast, can cut down on idle chitchat, and keeps the phone bills way down. It's also not terribly secure.

E-mails are vulnerable to being picked up by the most elementary hackers. Recognizing our dependency on e-mail, a number of companies offer different ways to protect these online interactions.

One of the latest services to hit the marketplace is from Disappearing Inc., which basically gives your e-mails a life expectancy. It works by encrypting the e-mail message before it is sent to the recipient. When the e-mail is opened, a "this-message-will-self-destruct-in-X-hours" message appears at the top. Nobody, including the recipient, can read the e-mail after it has expired.

Hushmail is another e-mail security firm that has emerged to offer a hand-holding experience for people looking for a happy medium between elementary password protection and hard-to-decipher high-tech options. In this case, you can sign up for a Web-based e-mail account that allows encrypted messages to be sent.

Neither solution is perfect, though. Disappearing e-mail does not currently encrypt attachments and cannot work with all e-mail packages. As of now, Disappearing E-mail works only with Microsoft Outlook 98 or 2000 running on Windows 95, 98, or NT. However, they plan to release Disappearing E-mail for use on Lotus Notes and other major e-mail systems by the end of the year. Similarly, Hushmail only works with other other Hushmail accounts, limiting its usefulness.

For the most flexible and comprehensive protection, you probably need to turn to the traditional e-mail encryption methods upon which these services are based. With the popular public-key method, you create a lock with two unique keys-one public, one private. The public key, copies of which you can distribute to any number of people, is used to "lock" a document intended for you. This document can only be unlocked by using the matching private key, which is held by you.

Probably the most popular public-key encryption package for Windows is produced by Pretty Good Privacy (PGP), and as its name suggests - it's pretty good. But it's not the most user-friendly option - you're left to fend for yourself when it comes to installing it, integrating it with your e-mail package, and wading through all the technical jargon.

These software packages come in both individual and commercial versions. The primary difference is that the commercial versions include centralized administrative features that make it easier to manage across the company. Also, corporate versions typically come at a cost whereas individual instances are still distributed for free.

The simplest way to minimally protect your documents is to use the password feature on the program you're using. For instance, if you're sending a Microsoft Word document, you can save it using a password, which would have to be entered to open the document.

Whether it's sensitive client information or simply communication you want to keep private, there are affordable options that provide every level of protection - from simple encryption to Mission Impossible-style self-destructing features. Keep it so that it's for your eyes only.

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