how to sending mail from an account in rails application with out given Password Credential?

I am implementing one of my client requirement..i.e., sending mail from an account in application with out given Password Credential i am also surprised after saw this method one of the website i.e.,

        http://ift.tt/28W51b7 

i am sending mail through this web ...but all sending mail updated in my gmail sent item... i have trying in this way by setting up in config file

     config.action_mailer.perform_deliveries = true

    config.action_mailer.default_url_options = { host: 'localhost', port: 9292}
      config.action_mailer.delivery_method = :smtp
      ActionMailer::Base.smtp_settings = {
      address:        'imap.gmail.com'or'imap.hotmail.com'or'imap.yahoo.com', # default: localhost
     port:           '993',                  # default: 25
     user_name:      'debasish.industrify2016@gmail.com',
        password:       'deb@industrify',
       authentication: :plain                 # :plain, :login or :cram_md5
      }