Electronics, including amplifiers, preamplifiers and source machines that are shipped with their original inner packaging and outer boxes have always been safely delivered to me. Double boxing is helpful, but has not been necessary.
Speakers shipped via UPS, Fedex and Bax Global in their original boxes have been damaged. I do not recommend shipping speakers unless it's only within one shipping zone or between two zones. A cross country shipment of speakers is a problem waiting to happen.
Shipping via air has less possibility of damage because it's handled fewer times. This is also why ground shipping within a zone, or between two zones is safer...less handling.