It's a phishing email if it asks you to click on a link. When you get redirected (probably to a PayPal cloned site), they will ask you to fill in your personal info from logins to cards/bank information. These kind of emails, in my experience, can be detected through the sender's email. If it isn't from the usual PayPal email addresses (see format for e.g.), it's probably fake. Notice the headers and footers as well. I would suggest that you login to your PayPal account by typing in the website on your browser (don't click on any links on the email) and login. Check your activities if it's the transaction is there. If it's not there, you may want to forward that email to PayPal's fraud department so they can trace and take action. If it is there and you did not do it, file a dispute and tag as fraud. Just follow the guidelines regarding the latter from the Help Pages.
