Sure, you can mail a package without a box, but it's not always the best idea. Though envelopes, padded mailers, and even sturdy bags can be used, these alternatives may not provide enough protection for your items, especially if they're fragile. Additionally, carriers often have specific packaging requirements which should be checked beforehand. Remember, the main goal is to ensure your package arrives safely at its destination. So, it's often worth it to take the extra step and box your items, even if it's not strictly necessary.