Environment: SQL Server 2012 reporting services 2012 w/ SharePoint 2010 Enterprise.
For SSRS reports hosted on SharePoint, the Data Alerts & Subscribe are grayed out or disabled.
What do you have to do?
You need to upload a SSRS and for the data sources, you’ll have to store the credentials or no credentials.
It’s not ideal for user-level security (e.g. via Windows Authentication) setup on the data source side but the requirement of data alerts and email subscription dictate that you need to stored the credentials or not have credential requirements.
If the New Data Alert option is grayed, the report data source is configured to use integrated security credentials or prompt for credentials. To make the New Data Alert option available, you must update the data source to use stored credentials or no credentials. – http://technet.microsoft.com/en-us/library/gg492251%28v=sql.110%29.aspx
what we ended up doing at a client’s was to create a SharePoint library for “report subscriptions” which is hidden from end-users. We added a service account to the data source & we store the credentials of the service in the report used for report subscription. And IT “controls” who receives the email. So after a user submits a request to get emails, IT goes in the security database & see’s if a user is fit to receive the email or not. So not all users may get approval to receive the email. That was a solution that we had to take to stay compliant.