KB20415: “(SMTP error) Permanent error during message delivery at host xxx.xxx.xxx.xxx” error occurs in the DELogs when attempting to deliver e-mail messages in MicroStrategy Narrowcast Server 8.x

SYMPTOM:
E-mail deliveries fail in Strategy Narrowcast Server 8.x with the following error message in the DE Logs:
In addition, the following error message occurs if the SMTP Log is enabled:
CAUSE:
A possible cause for this error is an invalid recipient e-mail address specified for Delivery Status Notifications at the 'E-mail (SMTP)' Information Transmitter level.
ACTION:
Verify that the e-mail address specified in the Delivery Status Notification tab of the 'E-mail (SMTP)' Information Source Transmitter is valid. Only one address can be specified in this field

For more information, refer to the following Strategy Knowledge Base technical notes:

• KB5699 (KB6200-7X0-0086) - The Delivery Status Notification options in Strategy Narrowcast Server Delivery Engine 7.x and 8.x
  
• KB15470 (KB6200-80X-1624) - How to use execution control documents to set delivery status notifications in Strategy Narrowcast Server 8.0.x
  
• KB9762 (KB6200-72X-0975) - How to generate the Strategy SMTP Protocol log file -- Strategy Narrowcast Server 8.x