Redmine

I am trying to configure email setting as per steps found at EmailConfiguration

I have configured configuration.yml (in /redmine/config/ and as well as in /etc/redmine/default/)

production:
   email_delivery:
     delivery_method: :smtp
     smtp_settings:
       tls: true
       enable_starttls_auto: true
       address: "smtp.gmail.com" 
       port: 587
       domain: "smtp.gmail.com" 
       authentication: :plain
       user_name: ######
       password: #######

When i configured above setting in configuration.yml at /redmine/config/ location, nothing happened still got the same error
attached in file Configured_1.jpg

But when i copy same file to /etc/redmine/default/ location i got different error
attached in file Configured_2.jpg

Please help, I'd like to start using this soon, but I need to work out the email configuration first.