Issue:

This issue with the email notifications was fixed with Cumulative update package 7 for SQL Server 2012 SP1, but we are seeing cases where the email notifications still do not happen, even after installing CU7 for SQL Server 2012 SP1.

Cause:

The PowerPivot for SharePoint update is not complete until the PowerPivot Configuration Tool is run.

Workaround:

Run the PowerPivot for SharePoint Configuration Tool to complete the CU7 update for PowerPivot for SharePoint, and then the email notifications will begin working.

Cumulative update package 7 for SQL Server 2012 SP1

http://support.microsoft.com/kb/2894115