How can I open android application activity from email?

We are sending user email as notification. Email body has Accept and Reject button.We are sending emails from android application as well as from web application to user. want to open an our application if user clicks on button contained in email. If user checks an email from android device and clicks on button, respective activity should be opened for user convenience. How can I open that activity if application is installed.

Thanks,

Prashant.