Based on customer response, categorize your subscribers based on availability, active readers, inactive readers and rarely interacted readers . With this, you will know who to focus on, how to focus and where to focus more and keep the goal of bringing inactive users to active usage and interaction.  Experiment on emails based on response: Every customer behaves in a unique way because they have their own likes and dislikes. So we need to make sure we appeal more to areas that love customers. For this you need to perform a simple response checker in which you need to send emails for a specific period and wait for a response, then send emails with a particular form of subject lines, send with appreciation or special offers and many such emails and wait. a response from the receiver and separate them accordingly. Some customers may be active users for a certain period of time, some will only accept liked emails, few will respect subject lines, and others might only click when they see spinning offers. the heads. This is because every customer has a unique functionality and you need to make sure your email appeals to everyone.