You can use the subscriber search options to quickly search your account for a subscriber and see what details you hold for them, what lists they are on and what campaigns they have been sent recently.
First, navigate to 'Subscribers' under the Collect tab in your account. This will bring you to the search page.
Choose the data to search by and enter your search text in the filter box (for email addresses this can be a partial text, for example the beginning of their email address). Click the magnify glass or press enter to search and the matching subscribers will be shown below.
You can expand the user details by clicking the arrow to the left, which will show the different options available to you. These include viewing the lists the subscriber is on, viewing a record of recent contact and viewing recent bounces.
Filter by list
Searching for a subscriber on this screen will default to searching the entire account. You can choose to search within a particular list(s) from this page, by choosing the filter options.