The numbers will vary based on a number of factors, such as the industry you are in, how well you have segmented your list, and what kind of content you are sending out every day. A general rule to follow is that an average open rate should be between 15-25% and the click through rate should be anywhere from 2-5%. But there really is no one standard number that can apply to all campaigns. You need to experiment and test different types of content in order to find what resonates best with your particular audience.