There is no directory of all email addresses, but people search sites and smaller email directories list some email addresses. Pipl, Intelius and Yasni are companies that offer email address searches.
Pipl allows users to search by name, email address, username or phone number. Location information is optional, but may make searches more accurate. Pipl advertises deep Web searches and an identity resolution engine that it claims make its searches more accurate than those of competitors.
Intelius requires a first name, last name and location to find an email address. Its search engine provides mailing address and location details in addition to an email address. It also allows users to confirm postal addresses using public utilities.
Yasni offers a free-form search rather than requiring specific information. It returns telephone and address information, email addresses, social networking profiles, news articles and public records. These public records include arrest records, marriage and divorce records, and driver's licenses.