diff --git a/www/common/cryptpad-common.js b/www/common/cryptpad-common.js
index 9f1d3f544..027b61929 100644
--- a/www/common/cryptpad-common.js
+++ b/www/common/cryptpad-common.js
@@ -656,6 +656,12 @@ define([
     };
     cursor.onEvent = Util.mkEvent();
 
+    // Mailbox
+    var mailbox = common.mailbox = {};
+    mailbox.execCommand = function (data, cb) {
+        postMessage("MAILBOX_COMMAND", data, cb);
+    };
+    mailbox.onEvent = Util.mkEvent();
 
     // Pad RPC
     var pad = common.padRpc = {};
@@ -1096,6 +1102,8 @@ define([
         CHAT_EVENT: common.messenger.onEvent.fire,
         // Cursor
         CURSOR_EVENT: common.cursor.onEvent.fire,
+        // Mailbox
+        MAILBOX_EVENT: common.mailbox.onEvent.fire,
         // Pad
         PAD_READY: common.padRpc.onReadyEvent.fire,
         PAD_MESSAGE: common.padRpc.onMessageEvent.fire,
diff --git a/www/common/outer/mailbox.js b/www/common/outer/mailbox.js
new file mode 100644
index 000000000..ab9d24d58
--- /dev/null
+++ b/www/common/outer/mailbox.js
@@ -0,0 +1,35 @@
+define([
+    '/common/common-util.js',
+    '/common/common-constants.js',
+    '/customize/messages.js',
+    '/bower_components/chainpad-netflux/chainpad-netflux.js',
+    '/bower_components/chainpad-crypto/crypto.js',
+], function (Util, Constants, Messages, CpNetflux, Crypto) {
+    var Mailbox = {};
+
+    Mailbox.init = function (store, waitFor, emit) {
+        var mailbox = {};
+        var ctx = {
+            store: store,
+            emit: emit,
+        };
+
+        mailbox.removeClient = function (clientId) {
+            // TODO
+            //removeClient(ctx, clientId);
+        };
+        mailbox.leavePad = function (padChan) {
+            // TODO
+            //leaveChannel(ctx, padChan);
+        };
+        mailbox.execCommand = function (clientId, obj, cb) {
+            var cmd = obj.cmd;
+            var data = obj.data;
+        };
+
+        return mailbox;
+    };
+
+    return Mailbox;
+});
+
diff --git a/www/common/outer/store-rpc.js b/www/common/outer/store-rpc.js
index 49bb7c960..aed0d5ab4 100644
--- a/www/common/outer/store-rpc.js
+++ b/www/common/outer/store-rpc.js
@@ -66,6 +66,8 @@ define([
             OO_COMMAND: Store.onlyoffice.execCommand,
             // Cursor
             CURSOR_COMMAND: Store.cursor.execCommand,
+            // Mailbox
+            MAILBOX_COMMAND: Store.mailbox.execCommand,
             // Pad
             SEND_PAD_MSG: Store.sendPadMsg,
             JOIN_PAD: Store.joinPad,