Lifecycle emails refer to the messages sent to people after they sign up for a product or service. When properly framed, they are empowering—like reminding someone to take a key action that is in line with their goals for using the product or service. The best lifecycle emails are dynamically based on activities users make—and don’t make—within the product, providing helpful tips on getting the most out of the product. It could take weeks or months before users get all of these.