action_mailerでメールを送るあれ

gmail.rb

# coding:utf-8
require 'action_mailer'

class GMails < ActionMailer::Base
  default from: "noreply@example.com"

  def sendmail
    mail(:to => "to@example.com",
         :subject => "Welcome test mail",
         :body => "hello!" )
  end

end

ActionMailer::Base.smtp_settings = {
  :enable_starttls_auto => :true,
  :address => "smtp.gmail.com",
  :port => 587,
  :authentication => :login,
  :user_name => "noreply@example.com",
  :password => "passpasss",
  :domain => "gmail.com"
}

GMails.sendmail.deliver