To check for and respond to messages you’ve received, you must log into your dashboard and click on either View ad activity or Access Messages and Contacts.
This will take you to the page with all your ad activity listed.
Below the graph, you’ll find two boxes—one labelled Contacts which tracks likes and comments made on your Facebook advertisement. If you click on the Messenger button to the right of these, you’ll be able to message the interested parties.
To the right of the Contacts box is another labelled Messages. These should be emails that go directly to the email you have linked to your account. However, if you do not find them there, then clicking on the message in the dashboard will bring up a box with the full email and a Reply button. When you click on that, you should be able to respond to the email sent to you.