If not managed rigorously, e-mail can ruin your life," says Marilyn Paul, a management consultant and author of "It's Hard to Make a Difference When You Can't Find Your Keys." That may sound dire, but having a messy inbox can lead to missed appointments and hours of wasted time. Here's how to show your e-mail who's boss:

Put your inbox on hold. Most people open their e-mail as soon as they arrive at work. Big mistake, says Paul. "You can quickly lose track of time and forget a meeting." Instead, start your day by reviewing your calendar and noting the three to five most important things you need to get done.

Avoid clutter. Be ruthless about getting e-mails out of your inbox. Set up folders to keep your messages organized. (In Microsoft Outlook, go to the File menu, select Folder, then New Folder, and choose Personal Folders as the location.) The most important one to set up is a Follow-up folder for messages that defy a ready response. Set a deadline for yourself to answer them, then write the deadline in your calendar.

Make time for cleanup. Each week, set aside two hours to go through your mail and delete as many messages as you can.

Try a new service. If you're not up to this level of organization, set up a Gmail account ( and have your office messages forwarded there. With Google's service, you "archive" rather than delete and searching old e-mails is a breeze.