+/** @brief Mailboxes: Network rendez-vous points.
+ * @ingroup s4u_api
+ *
+ * @tableofcontents
+ *
+ * @section s4u_mb_what What are mailboxes
+ *
+ * Rendez-vous point for network communications, similar to URLs on
+ * which you could post and retrieve data. Actually, the mailboxes are
+ * not involved in the communication once it starts, but only to find
+ * the contact with which you want to communicate.
+
+ * Here are some mechanisms similar to the mailbox in other
+ * communication systems: The phone number, which allows the caller to
+ * find the receiver. The twitter hashtag, which help senders and
+ * receivers to find each others. In TCP, the pair {host name, host
+ * port} to which you can connect to find your interlocutor. In HTTP,
+ * URLs through which the clients can connect to the servers.
+ *
+ * One big difference with most of these systems is that usually, no
+ * actor is the exclusive owner of a mailbox, neither in sending nor
+ * in receiving. Many actors can send into and/or receive from the
+ * same mailbox. This is a big difference to the socket ports for
+ * example, that are definitely exclusive in receiving.
+ *
+ * A big difference with twitter hashtags is that SimGrid does not
+ * offer easy support to broadcast a given message to many
+ * receivers. So that would be like a twitter tag where each message
+ * is consumed by the first coming receiver.
+ *
+ * The mailboxes are not located on the network, and you can access
+ * them without any latency. The network delay are only related to the
+ * location of the sender and receiver once the match between them is
+ * done on the mailbox. This is just like the phone number that you
+ * can use locally, and the geographical distance only comes into play
+ * once you start the communication by dialling this number.
+ *
+ * @section s4u_mb_howto How to use mailboxes?
+ *
+ * Any existing mailbox can be retrieve from its name (which are
+ * unique strings, just like with twitter tags). This results in a
+ * versatile mechanism that can be used to build many different
+ * situations.
+ *
+ * For something close to classical socket communications, use
+ * "hostname:port" as mailbox names, and make sure that only one actor
+ * reads into that mailbox. It's hard to build a prefectly realistic
+ * model of the TCP sockets, but most of the time, this system is too
+ * cumbersome for your simulations anyway. You probably want something
+ * simpler, that turns our to be easy to build with the mailboxes.