Redmine

Hello,
I have windows 2008 r2 server with redmine 2.4.1, MS exchange 2013 as a mail server.
I tried to configure email settings in redmine, i followed this article http://www.redmine.org/projects/redmine/wiki/HowTo_configure_Redmine_to_mail_to_MS_Exchange_server.
But when i'm inserting those email settings into configuration file, and someone trying to connect to our redmine server page, both thin_* services are going down.
What could be the reason of that problem?

my email settings:
production:
email_delivery:
delivery_method: :smtp
smtp_settings:
enable_starttls_auto: true
address: "xxxxxx.exchange.com"
domain: "exchange.com"
port: 587
authentication: :login
user_name: "redmine@exchange.com"
password: "xxxxxxxxxx"