Listrak's legacy filtering system is being upgraded in Segment Filter 2.0. At this time there is no plan to sunset the Legacy Filter system.
Listrak's filtering system takes your entire list of contacts and excludes contacts based on whether or not they meet the filter you apply.
Apply Listrak's legacy filters in many different places across the platform, such as:
A New Message
Your Contact List
Creating a Split Test
Learn more about the segmentation and filtering capabilities in the below content: