I'm facing an issue with some deliveries that get rejected from an initial population (around more than half the initial population doesn't receive their deliveries) and I don't know why this is happening. Normally, everything runs fine.
You can see my example below (the red cells are my current issues of rejected deliveries).
This is what I get in my delivery logs, nothing particular to declare :
But here, I can see that almost all of the deliveries for those recipients got an alert with the status ignore, why this is happening ? The address is "not specified" but some recipients still receive their deliveries.
Is there anything special I can look into to see what goes wrong with those deliveries and how to solve that ?