Report on 'Not Sent' subscribers through email sends

• To report on the Email Activity in question, you will need to gather the JobID (also referred to as SendID) for each email send. 
• Navigate to Automation Studio and create a new Data Extract Activity.
• Next to Extract Type, select "Tracking Extract" in the drop down. 
  • Note: If Tracking Extracts are not available in your account, please reach out to Global Support to enable this feature.
• Take note of the 'File Naming Pattern' defined (exported as a .zip file). 
• Under the 'Configuration' tab ensure that at minimum these are checked (others can be added as necessary :
  • Extract Not Sent
  • Extract Subscribers
  • Extract Unsubs
• Include a date range that would capture the engagement in question. 
• Include the SendIDs under the 'SendIDs' input box, separated by commas and no spaces.
  • ex. ) 1234,123,321,134
• Save the Data Extract Activity.
• Configure a File Transfer Activity which will be used to place your Tracking Extract on your account FTP.  If you do not have a FTP created or are uncertain of the login credentials for it you will want to reach out to your local account administrator. 
• Under the 'Properties' tab, ensure that 'Move a File From Safehouse' is selected. 
• Under the 'Configuration' tab, input a matching 'File Naming Pattern' and select 'Destination' of 'FTP'. 
• Save the File Transfer Activity. 
• Create an Automation that runs on a cadence of your choosing and place the Data Extract at Step 1. Then place the File Transfer Activity at Step 2.
• Once the Automation completes, check your FTP for a file that matches the 'File Naming Pattern' specified previously.

Note:  'Not Sent' Data does not populate immediately for a Job. It becomes available after processing is complete at the job level.
For Triggered Sends, data becomes available shortly after each individual send is processed.
For Bulk Sends, data becomes available after the entire send job is completed, to ensure consistent reporting.

Additional Documentation

• How to Configure, Run, and Review a NotSent Extract
• Details on Configuring a Tracking Extract
• Create a File Transfer Activity
• Details on NotSent output data 
• Not Sent Reasons and Descriptions