What are inactive contacts?
Inactive contacts do not receive any newsletters and autoresponders. These contacts have been removed from your list manually, unsubscribed, bounced or have not confirmed their subscription yet. In order to preview them please go to Contacts>>Search Contacts, click View all contacts, in the top right corner click the Show type list and choose the group.
Inactive contacts cannot be removed, but they do not count towards your total for billing purposes in a paid account. Only in a free trial these contacts count towards your limit.