swiftmailer:
   transport:            smtp
   username:             ~
   password:             ~
   host:                 localhost
   port:                 false
   encryption:           ~
   auth_mode:            ~
   spool:
      type:                 file
      path:                 '%kernel.cache_dir%/swiftmailer/spool'
   sender_address:       ~
   antiflood:
      threshold:            99
      sleep:                0
   delivery_address:     ~
   disable_delivery:     ~
   logging:              '%kernel.debug%'