The phisher's goal is to persuade a recipient that he has received a legitimate message, which must be replied to immediately.

Energy imperatives aside, this is a legitimate message - a truism Africa needs to hear.

But this can cause problems of its own for those who are sending a legitimate message to a recipient they don't know.

For now, the service is mostly a way to get around the problem of junk mail filters blocking legitimate messages from the company to its users.

Providers may fear liability should a legitimate message of an emergency nature be blocked.

If you have a public e-mail address you can receive hundreds of spam messages for every legitimate message that arrives.

Nearly all legitimate e-mail messages from companies to their customers contain an item of information that is not readily available to phishers.

Blocking software may inadvertently prevent a legitimate e-mail message from reaching a subscriber.

Demands for Mr. Pearl's release were made in two apparently legitimate, e-mail messages to news organizations.

That often results in the rejection of legitimate noncommercial messages sent to addresses on mailing lists.