I found this on the PCMag site:
You can password-protect your in-box using OE's Identities feature. From the menu select File | Identities | Add New Identity. Define a secondary identity, which you will not actually use; do nothing but give it a name. Do not switch to the new identity when prompted. Then select your own main identity and click on the Properties button. Check the Require a Password box and enter the password you want to use. Click on OK, then on Close.
After doing this one-time procedure, you must always close OE by choosing Exit and Log Off Identity from the File menu rather than merely selecting Exit. This menu item is disabled unless multiple identities are defined. (That's why you created the nonfunctional secondary identity.) When you log off in this way, nobody can launch OE without supplying the password.
The initial release of Outlook Express 6.0 had a problem with switching identities. If you use version 6.0, be sure to update it with Service Pack 1.
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There are a number of programs that filter internet stuff.
Off the top of my head, NetNanny comes to mind. If you use Internet Explorer or Netscape, check tools, options, Security, Privacy, Content, and Advanced areas for some internet controls. However, some of them become more annoying than not having them in place, so if you are experimenting, do one at a time, so you can reverse easily if you have a problem. An internet search for pornography filter will give you some more options to check out.