first,last,username,email
John,Doe,johndoe,John.Doe@email.com
JANE,DOE,JANEDOE,JDOE@EMAIL.COM
Bob,Smith,bobsmith,Bob.Smith@email.com
Bill,Nelson,BILLNELSON,BILL.W.NELSON@EMAIL.COM

$csv_row = file($_FILES['csv_file']['tmp_name']);

  // loop around
  if (is_array($csv_row)) {
    foreach (array_slice($csv_row,1) as $row) {

      // split into values
      $csv_data = explode(",", $row);

     // Take forth value $csv_data[3] which is the email
     $email = $csv_data[3];

     //Verify domains
     $email_domain = substr(strrchr($email, "@"), 1);
     $domains = array('Email.com', 'EMAIL.COM');


          // Validate email format
          if ( !is_email( $email ) ) {
            echo '<p><code>' . $email . ' is not a valid email.</code></p>';
          } else {
            echo '<p><code>' . $email . ' is a valid email.</code></p>';
          }

         // Validate email domain
          if ( !in_array($email_domain, $domains)) {
            echo '<p><code>' . $email_domain . ' is not a valid email domain.</code></p>';
          } else {
            echo '<p><code>' . $email_domain . ' is a valid email domain.</code></p>';
          }
      }
    }

John.Doe@Email.com is not a valid email.
Email.com is not a valid email domain.

Jane.Doe@Email.com is not a valid email.
Email.com is not a valid email domain.

Bob.Smith@Email.com is not a valid email.
Email.com is not a valid email domain.

BILL.W.NELSON@EMAIL.COM is a valid email.
EMAIL.COM is a valid email domain.