Newsletter Status Codes
If you'd like to check the status of a newsletter deployment, you can do so in Admin > Newsletter Manager > Pending
You'll see a table similar to the following example:
The Status column will contain one of 3 values: P, N, or E.
P: The newsletter has been processed and sent to your ESP (the Sent Count does not increment for this status code).
N: The newsletter has not yet sent because of an issue, the Scheduled Task will retry deploying every 15 minutes and incrementing the Sent Count until it has reached 4 failed attempts (at which point the Status will change to E).
E: You will see this in the event of an error, after the status N has iterated through all 4 send attempts.