Under the program, patent applicants receive an e-mail notification of office communications instead of paper mailings. An e-mail is sent to program participants when new office communications are available for viewing and downloading in Private PAIR, the patent application information retrieval system that allows applicants electronic access to the entire file history of their applications.
“We received very positive feedback from applicants who participated in the pilot program,” said Acting Under Secretary of Commerce for Intellectual Property and Acting Director of the USPTO John Doll. “Not only have we dramatically reduced paper processing and mailing costs but also expedited notification allowing applicants to take full advantage of their time period for reply to an office action.”
The e-Office Action program minimizes the possibility of lost or delayed postal mail and makes it faster and more efficient for participants to process and docket USPTO communications in electronic format, thus reducing processing costs.

For more details visit  : http://www.uspto.gov/web/offices/com/speeches/09-13.htm