Can I email the electronic acknowledgement receipt?

EFS-Web gives you the option, on the "Pre-Acknowledgement Receipt" screen and the "Acknowledgement Receipt" screens, to email information about the submitted application or follow-on documents. You won't be able to email the PDF version of the receipt using the "E-Mail Receipt Info" link, but you will have an email auto-populated with the application number and date submitted which can be sent to anyone of your choosing.

An email client is required to be configured for use with the browser for the "E-Mail Receipt Info" link to work.

USPTO FAQ - Questions and Answers (29AUG2008)