To varying degrees, all Internet service providers will keep your e-mail stored even after you download it.

The intent is to help you, not to subvert you in some evil way.

If you get crucial e-mail, having it stored on your ISP's server is of great help if your hard drive goes up in flames and you need copies.

Some people access their e-mail on one computer during the day, but check it again at home on another. If the e-mail stays on the ISP's server, it is possible to get all the day's communications during the evening download.

If e-mail were not stored, at night you would get only e-mail that arrived after the day check.

You can control how e-mail is handled on the server through your e-mail program's settings.

In Outlook Express, go to Tools and click on Accounts.

In the Internet Accounts dialog box, click on the Mail tab, highlight the reference to your ISP, then click on Properties.

Click on the Advanced tab. In the Delivery section, choose whether you want e-mail stored on the server, and for how long.

Other e-mail programs have similar options.