What is a List?
A List is place to store email addresses, phone numbers, or other values. Lists can contain one or more single-column rows of data.
You can mix data of various types, phone numbers and emails for example, in the same List. You can add new values to a list or remove them.
A List can be quickly queried programmatically via the API or, using the Query URL feature, by a simple Http GET request.
A single query can search one or more specified Lists. Each list queried counts as a billable transaction.
Your query can specify a maximum lookback period based on when items were added to the List. You can configure your List to automatically delete items based on the item's age i.e when a specified period of time has elapsed after the item was added.