Copy Donation Receipt To Admin

/**

 * Send the donation receipt to the site admin as well.

 *

 * @param   string|string[] $recipients

 * @return  string[] $recipients

 */

function en_copy_donation_receipt_to_admin( $recipients ) {

    /** 

     * If it isn't an array, cast it to one. 

     */

    if ( ! is_array( $recipients ) ) {

        $recipients = (array) $recipients;

    }    

    /**

     * Add the admin email address. To user a different 

     * email address, just replace get_option( 'admin_email' )

     * with the email address you want to add. For example: 

     * 'eddie@example.com' 

     *

     * Note: The quote marks are required.

     */

    $recipients[] = get_option( 'admin_email' );

    return $recipients;

}

add_filter( 'charitable_email_donation_receipt_receipient', 'en_copy_donation_receipt_to_admin' );