Message to customer

When placing an order as sent. Why does not an email go out to the customer that the order has been sent?

Hello,
It does go to the customer. If I place an order, I will receive an email. If the customer does not receive the email there is some malfunction.

Hello
Yes, the email is received by the customer when the customer places an order. But when we mark it as sent. Then an email will not be sent to the customer stating that the order has been sent

Yes, but you send with a click from the order page after you sent the parcel

Ok but How?

I never use this system but I think should work (see attachment)

Thanks