Sending mail with devise and Gmail smtp server

I am using Devise :confirmable and :recoverable module to confirm a user and to let him recover his password if he forgets it. Everything is going fine, the mail gets generated and I can see it in the server log, but then I am facing errors and the mail is not delivered to the mailbox. The SMTP settings for my environment.rb file is :

require 'tlsmail'
Net::SMTP.enable_tls(OpenSSL::SSL::VERIFY_NONE)
ActionMailer::Base.raise_delivery_errors = true
ActionMailer::Base.perform_deliveries = true
ActionMailer::Base.delivery_method = :smtp

ActionMailer::Base.smtp_settings = {
  :enable_starttls_auto => true,  #this is the important shit!
  :address => 'smtp.gmail.com', #'localhost', 
  :port => 587,
  :tls => true,
  :domain => 'mail.google.com',  # mail.customdomain.com if you use google apps
  :authentication => :login,
  :user_name => 'jatinkumar.nitk@gmail.com',
  :password => '_secret_password'
} 

If the :address is 'smtp.gmail.com' , then i get the following error:

SocketError (getaddrinfo: Name or service not known):

If i set the :address to 'localhost', then i get the following error:

Errno::ECONNREFUSED Connection refused - connect(2)

I don't know what this :address means, a newbie for all this stuff. On running uname -a, i get

Linux jatin-ubuntu 2.6.32-24-generic #38-Ubuntu SMP Mon Jul 5 09:22:14 UTC 2010 i686 GNU/Linux

In my /etc/hosts file the entries are :

127.0.0.1   localhost
127.0.1.1   jatin-ubuntu

*#74.125.93.109   smtp.gmail.com 
#The above entry added by me*

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

When I uncomment the 'smtp.gmail.com' address in the /et