Hello, this is the customer support of GeekJack. Thank you very much for your feedback.
The 'AIRMAIL' shipping method has a size limit that may be exceeded during actual packing. We apologize for the inconvenience.
You could not use this shipping method this time, but the orders can be shipped very cheaply via 'AIRMAIL' if the size allows, so we are offering 'AIRMAIL'.
Thank you very much for your understanding.