Email Request
In case “Use e-mail address” option is selected, the new password is sent by e-mail to the address stored for the user in Active Directory.

If you check To send confirming message by E-mail, the user receives a link to confirm the reset first (see How Password Reset Works). If you uncheck it, the password is reset at once and the new password is sent by e-mail.
In Administrative Options, enter the domain name, the user principal name and the password of the account that has rights to reset passwords. The password is not shown after saving; leave the field empty to keep the saved one.
Note: you need to enter the fully qualified user principal name, in the user@domain format.
In E-mail Options, set the Subject, the Confirming E-mail message ({0} is replaced with the confirmation link) and the E-mail message ({0} is replaced with the new password).

Now click “OK” to save the settings and return to the web part. Or click “Apply” to save the settings and continue adjustment (in this case the settings block will stay opened).