Question: I have a user who is not listed in the Notify field in DataLink manager, and yet he is receiving email notification about DataLink upload validation failure, see screenshot of the email below. Why is that? And how can I take him off such email notification?
Answer: Per KB article Configure Agent email notifications, there are two types of email notifications that may be sent when a DataLink connector runs:
One is an email notification sent by DataLink which is based on the success or failure of the connector run. It is not based on the validity of the data loaded into the Apptio application.

The Apptio application can send out a separate email notification based on the validity of the data that was uploaded. The Apptio application's notification will be sent to all Apptio application users assigned to a role containing the "AdministerDatalink" permission. Examples are the "Admin" and "Datalink Admin" roles.
The email in the screenshot the customer receives (shown below) is about the validity of the data uploaded. This means the user has been assigned either the "Admin" or "Datalink Admin" role in the Apptio application; this email was not sent as a result of the configuration of a DataLink connector. If you remove the "Admin" role and the "Datalink Admin" role from the user in the Apptio application, he will no longer receive such notifications.