Enable debug mode and maximum error reporting in Joomla global configuration then retry to see if any errors output. If none check your server error log for any fatal errors. If none contact your host to see if the emails are being blocked for some reason. CB should throw an error if the mailer settings aren't working as sendmail, phpmail, or smtp would error. If they're not erroring it typically means the email stopped before sending in the mailer it self. The from email address should have the same domain as your mail server otherwise it's common for mail servers to block the outbound mail.

PHP version: 5.3.29

PHP 5.3.29 is EOL (end-of-life) by PHP foundation. Its last release was August of 2014. So your PHP is about to be 3 years of out date. I highly suggest contacting your host and having them upgrade you to at the very least PHP 5.6. This could be part of your issue. We do not test PHP 5.3 anymore.