When contacts forget their password, you can send a password reset link to them.
To send a password reset link to a contact,
Go to the contact's details page.
Click the Actions menu on the details page and select Send Password Reset Link.
Incase if the outgoing mail server is not configured, or if the contact doesn't have a primary email ID, or if the contact doesn't have a unique email ID, then the email will not be sent. In such cases, a popup with the password reset link will be displayed to the administrator, who can share the link with the contact.