Trading in this game is delicate, because there's a risk if it's made too easy that a profit-seeking culture will be created that seems rather antithetical to the vibe people love about this game. I think a simple improvement that would avoid this pitfall and have interesting trade-offs of it's own would be to let people send the full contents of a Storehouse item slot through the mailbox. Both sending and receiving players should have the Storehouse unlocked, and the item should be tradable at the appropriate player levels. The receiving player gets a single mailbox slot filled with a "Crate" that is openable at the locksmith. The crate item would be titled along the lines of, for example "Crate of Orange Juice (100x)".
I believe this would be an improvement to trading, as it would allow items to be traded at higher quantities while still requiring game systems (the Storehouse) to be interacted with. Potentially there could be a cooldown on Storehouse item slots after such a trade, to prevent abuse.
