Could there be a system so that players could become a "mailman"?
My idea: there's a post office in most towns and city's...if they send a package or letter it would take x amount of time to get it to the recipient Say, an in game week. But if you work there you can deliver their mail yourself (and other people's stuff) for a bit of coin?
Would this work or is there just going to be a boring automatic mail system? Or a not so boring portal system? Or just a courier network? is there even going to be a mail system?