10 Towns Communication

What have y'all done for communication between the Ten Towns? I.e. if a PC wants to send a message from one town to another? I'm thinking about having a general postman that goes out on horse to the next town every few days, and maybe having the Speakers keep trained crows to carry messages. Otherwise, they may have to ask the townsfolk to see who is traveling to where they want to go and carry a message with them. In any case, might invoke a luck check to see if the message makes it since there are so many threats around Icewind Dale. Thoughts?