20% have never sent an e-mail

Roughly one-fifth of all U.S. households are disconnected from the Internet and have never used e-mail, according to research firm Parks Associates.

A recent phone survey of U.S. households by Parks found 20 million households are without Internet access, approximately 18% of all U.S. households.

"Nearly one out of three household heads has never used a computer to create a document," said John Barrett, director of research at Parks Associates, in a statement. "These data underscore the significant digital divide between the connected majority and the homes in the unconnected minority that rarely, if ever, use a computer."

Age and education are factors in this divide, Parks found. One-half of those who have never used e-mail are over 65, and 56% had no schooling beyond high school.

Parks found 7% of the 20 million disconnected homes plan to subscribe to an Internet service within the next 12 months. In 2006, Parks found that 29% of all U.S. households -- 31 million homes -- did not have Internet access, citing low perceived value of the Internet.

"Many people just don't see a reason to use computers and do not associate technology with the needs and demands of their daily lives," Barrett said.