How contacts are collected in email campaigns
Recipients added to an email campaign list are based on the cumulative selection of the various methods available.
See our help article
here on setting up a campaign which shows you how to select recipients for the various methods
Recipients that appear in multiple results will not be duplicated and
any unsubscribed contacts will not be added to the final recipient list.
The final recipient list is only generated & verified at the time of actually sending the campaign. As such the number of recipients sent will most likely vary from the estimated number displayed here