Many penetration testers gather user names and e-mail addresses, as this information is frequently used to log on to targeted systems.
The most commonly employed tool is the web browser, which is used to manually search the target organization's website as well as third-party sites such as LinkedIn or Jigsaw.
Some automated tools included with Kali can supplement the manual searches.
E-mail addresses of former employees can still be of use. When conducting social engineering attacks, directing information requests to a former employee usually results in a redirect that gives the attacker the "credibility" of having dealt with the previous employee. In addition, many organizations do not properly terminate employee accounts, ...