For the email marketer, simulating or testing a campaign prior to the full send can result in improved open, click and conversion rates, as well as protect the relationship you have earned with your customer by validating the value you are communicating in the email is relevant and important to them, resulting in lower unsubscribe rates.
For the email marketer, create space in your calendar to do a retrospective review of campaign performance; not just in terms of numerical results, but ask yourself the question, “what did we learn about our customer in that test that we can apply moving forward?”