problem with ActionMailer/SMTP

hi, i'm trying to make the user account confirmation work in my site, but i couldn't fix this error,

Processing UsersController#create (for 189.85.180.50 at 2009-09-23 16:44:30) [POST]   Parameters: {"commit"=>"Criar novo usuário", "authenticity_token"=>"UX+z7gZGHLo5+1LkW0duFvu69YiHC7H0baMY/Sbtyi8=", "user"=>{"password_confirmation"=>"paulogeyer", "password"=>"paulogeyer", "login"=>"paulo", "email"=>"paulogeyer@gmail.com"}} Sent mail to paulogeyer@gmail.com

ArgumentError (wrong number of arguments (3 for 2)):   /usr/lib/ruby/1.8/net/smtp.rb:525:in `start'   app/models/user_observer.rb:3:in `after_create'   /usr/lib/ruby/1.8/observer.rb:185:in `notify_observers'   /usr/lib/ruby/1.8/observer.rb:184:in `each'   /usr/lib/ruby/1.8/observer.rb:184:in `notify_observers'   app/controllers/users_controller.rb:19:in `create'   /usr/lib/ruby/1.8/phusion_passenger/rack/request_handler.rb:95:in `process_request'   /usr/lib/ruby/1.8/phusion_passenger/abstract_request_handler.rb: 207:in `main_loop'   /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb: 378:in `start_request_handler'   /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb: 181:in `spawn_application!'   /usr/lib/ruby/1.8/phusion_passenger/utils.rb:183:in `safe_fork'   /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb: 153:in `spawn_application!'   /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:272:in `spawn_rails_application'   /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb: 80:in `synchronize'   /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb: 79:in `synchronize'   /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:255:in `spawn_rails_application'   /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:154:in `spawn_application'   /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:287:in `handle_spawn_application'   /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `__send__'   /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `main_loop'   /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:196:in `start_synchronously'   /usr/lib/phusion_passenger/passenger-spawn-server:61

Rendering /var/www/100empresas/public/500.html (500 Internal Server Error)

here follows the code

user_observer.rb line #3

2: def after_create(user) 3: UserMailer.deliver_signup_notification(user) 4: end

users_controllers line #19

18: @user = User.new(params[:user]) 19: @user.register! if @user && @user.valid? 20: success = @user && @user.valid?

and my email configuration from environment.rb

  config.action_mailer.delivery_method = :smtp   config.action_mailer.smtp_settings = {     :address => "smtp.gmail.com",     :port => 587,     :authentication => :plain,     :domain => "empreendedor.com.br",     :user_name => "****@empreendedor.com.br",     :password => "****"   }

any ideas? It is quite obscure to me