Each plan has a restriction on the number of subscribers that can be stored on its lists. This limit is based on the combined total of all subscribers present in all your lists. If a subscriber is present in multiple lists, they will be counted multiple times towards this limit. For instance, if an email address is present in six separate lists, it will be counted as six subscribers.

Unsubscribes do not count towards the limit on your plan. Additionally, any hard bounces and complaints are automatically marked as unsubscribed and hence, are not included in the subscriber limit of your plan.