Almost anything can be mailed to Hawaii, with a few exceptions and special‑permit items.
For these items, contact the USPS or the Hawaii Department of Agriculture for specific instructions.
USPS flat‑rate boxes are often the most convenient and cost‑effective option, as pricing is based on box size, not weight. Private carriers (FedEx, UPS) are available but typically cost more. Consider insurance for valuable or fragile shipments.