The emails states this:
Receipt Number: WACxxxxxxxxxxx
Application Type: I765, APPLICATION FOR EMPLOYMENT AUTHORIZATION
Your Case Status: Post Decision Activity
On June 19, 2015, we approved your Form I765, APPLICATION FOR EMPLOYMENT AUTHORIZATION, Receipt Number WACxxxxxxxxxxx. We will mail your approval notice. Please follow the instructions in the notice. If you move, go to www.uscis.gov/addresschange to give us your new mailing address.
For approved applications/petitions, post-decision activity may include USCIS sending notification of the approved application/petition to the National Visa Center or the Department of State. For denied applications/petitions, post-decision activity may include the processing of an appeal and/or motions to reopen or reconsider and revocations.