You can use the List Builder app to look at your previous sends – and then compile a list of all of the people who received your email but didn’t read it. You can set the app to create this new list inside your lists section – making it really easy to set up a new send to all of these people.

You can also use the List Builder app to create lists of people who clicked on links within your mailer. This is a great way to follow up people based on how they interacted with your sends.