Content Security Policy setting in apache for Roundcube Webmail

[vishnuduttp]

I have been Using Round Cube 0.9.5.
Recently I have implemented https and installed the certificates in my apache server (Apache 2.2.15). I have hardened the server and used secure headers in apache.But while adding the Content Security policy rules Iam having difficulty in accessing the website. Whether the roundcube is using any other websites while loading the pages or frames. I have also tried with a liberal rule in my server. But it didn't help. The rule I have added in my server is as follows,

Header set Content-Security-Policy  "default-src * "
Thanks in advance.