Is the era of free e-mail coming to a close? That's the question many observers asked when Yahoo and AOL unveiled a plan to charge businesses for every e-mail sent to one of the more than 40 million accounts the companies host. By doing so, the companies hope to cut down on spam.

While AOL and Yahoo promise that individual e-mail will remain free, the original plan has drawn protests from, among others, the Direct Marketing Association, which points out that many businesses market themselves via e-mail.The outcry has led AOL to modify its stance slightly, recasting the idea as an optional certified mail-type service for businesses that send a lot of e-mail.

The benefit? For between a quarter of a cent and a penny, companies can make sure their e-mail survives spam filters, which intercept up to 15 percent of legitimate e-mail. Goodmail Systems, a privately held Silicon Valley company, will run the service.

P.S. You may hate the idea of paying to send e-mail, but compared with other methods of reaching customers, it's still peanuts.

$0.24....a post card
$0.39....a letter
$0.10....a minute of long distance
$ overnight package