clicking on new unread mail in gmail inbox and interacting with the element using Selenium webdriver

Please help me out im stuck Im working in project where i have to buy the product in some website and ill get the mail in gmail i have to click on incoming mail ( unread mail )and interact with the clicked element. So far i have buyed the product and now im stuck with the gmail im not able to open the unread mail and interact with the element when clicked unread mail. Please help me out.