Finger is the tool for discovering user information by using well known finger service. To use the finger tool enter the User@Host in the Finger Input box, and click on the Finger button .The results will be shown in the Finger Response section. Using Finger tool makes possible to get "Abuse Address" of remote host.For example to get the abuse address of prontomail.com you should type email@example.com in the finger input section. As a result you will receive firstname.lastname@example.org (for prontomail.com) in the finger response section.
Software that can be used as an alternative to Finger: