This issue occurs when the segment is assigned a specific Package that contains the email message has not been properly configured. To resolve the issue, enter or verify the settings below:
  1. Open the Package that contains the email and select 'Edit package information'.
  2. On the 'Edit email package' screen, ensure that a Message and Export definition are specified under 'Primary content'. If they are not specified, enter the information.
  3. Save the changes to the Package.
  4. Go back to the Marketing Effort and refresh the segments, then re-export the Marketing Effort.
  5. The start email job button should now be available to begin the email process.