ActionMailer not send and not generate errors

I have insert in envirmonment.rb

ActionMailer::Base.delivery_method= :sendmail

and i have created a mailer model:

class MyMailer < ActionMailer::Base   def mail_authentication(user)     from ""     recipients user.mail     subject "| NERTO | Conferma Registrazione"     body :user => user   end end

with his template

For sending a letter i have insert in a controller this: MyMailer.deliver_mail_authentication(@user)

but the mail don't is sent. In the console there are no errors.

Why? Where is the problem?

i try also with: ActionMailer::Base.smtp_settings = {   :address => "",   :port => 25,   :user_name => "",   :domain => "",   :password => "*****",   :authentication => :plain }

but it the same thing. Thanks