I think most people believe the meaning of “Email Delivery History” is: ‘if, and when emails were delivered’,A couple of errors in email delivery with Hotmail and MSN.
and that the meaning of “Queued mail for delivery” is: 'queued and still waiting to be delivered’ until the “Email Delivery History” is updated to show when it was delivered.
“Queued” implies waiting to ‘get on the bus’, in other words ‘not going anywhere’ or undelivered.
Not having a legend explaining what the codes mean in plain, non-IT language is what is causing the doubt many are expressing.
Could these codes be made ‘clickable’ or when ‘hovered over’ to reveal their plain, non-IT language meanings?