When a ministry says something is wrong, these two say whether the platform agrees. The logs are errors the apps themselves reported; the queue is mail that has been accepted but not yet delivered.
Open the error logs from the service they came from.
Read the newest first, with the tenant they belong to.
An error against one ministry is theirs; the same error against all of them is ours.
Open the Mail service and read its queue.
A queue that is growing means delivery is failing, not that nothing was sent.