I assume you want to close it. You need to wait for the "close" button to be visible and then click it. Here is what works for me as is:
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;
public class Test {
public static void main(String[] args) throws InterruptedException {
WebDriver driver = new FirefoxDriver();
WebDriverWait wait = new WebDriverWait(driver, 10);
driver.get("http://www.bestbuy.com/");
driver.manage().window().maximize();
// wait for the close button to appear
WebElement closeButton = wait.until(ExpectedConditions.elementToBeClickable(By.cssSelector(".email-submission-modal .modal-header button.close")));
closeButton.click();
// do smth
}
}