I'd like the idea of creating contracts for other players to move your goods, person creating the contract sets an "insurance" price (an upfront bill that the courier pays incase the cargo is lost or stolen) and pays the delivery fee in full (whatever price they set). Once the courier has paid the "insurance" the cargo is visible in their warehouse, upon delivery to the destination port, a notification is sent to the player that set the contract and the money is released to the courier.
For it to work, it would not send any notification to the player that set the contract until the cargo has been delivered or lost.
Players could steal this cargo from the courier and deliver it or keep it (just like any goods on player ships or the basic cargo missions). Obviously cargo/passenger mission items would have to be exempt from the delivery contracts.
This would be great for times when you need to move stuff to another port but don't have time, can't be bothered or whatever and could also push more players into the open world moving goods around, other than just warships and the occasional trader.