- Enter an email address (e.g. firstname.lastname@example.org) to try and find out more about the owner of a particular email address.
- Enter @company.com for a list of users at a particular domain.
- Enter a partial address for results beginning with those characters.
Don't neglect one important source of information: the search engines! You can try a search for an email address on Google or Yahoo! by simply entering the email address in full - this will return all pages that contain that address.