The problem I am describing here is related with setting up custom domain for Window Azure CDN in your Office 365 (Professional and Education) account.

 

Here are the details:

-           Your custom domain:                                      mydomain.com

-           Your Azure Storage CDN URL:                         azurestorage.blob.core.windows.net

-           Custom Domain for Azure CDN:                      storage.mydomain.com

Now you would like to set custom domain name for Azure CDN:

-           You would want to point storage.mydomain.com to your Windows Azure CDN endpoint.

-           To setup CNAME entry you would need to set something similar to this 'd2e332d9-a34d-123d-de34-b43dc232c2a4.storage.mydomain.com' pointing to verify.azure.com for domain verification.

-           However in Office 365 Domain handler (for professional & student) doesn't allow 3rd Level domain format as ‘xxxx.storage.com".

 

The problem is only because Office 365 Domain handler (for professional & student) does not support 3rd level domain, and it is only supported in Office 365 enterprise. You can use the following two options to solve your problem:

  1. You can use other 3rd party domain registrar instead of using Office 365 domain setup
  2. Or you can upgrade your Office 365 subscription to Enterprise level

 

You can learn more details in the link below:

http://social.msdn.microsoft.com/Forums/en-US/windowsazuredata/thread/585e7c66-76bb-465f-b17a-ae475ffc9c30