diff --git a/frontend_tests/node_tests/compose.js b/frontend_tests/node_tests/compose.js
index 6e8bc63a6d..286a5869bd 100644
--- a/frontend_tests/node_tests/compose.js
+++ b/frontend_tests/node_tests/compose.js
@@ -284,16 +284,7 @@ people.add(bob);
     assert(reify_message_id_checked);
 }());
 
-(function test_mark_rendered_content_disparity() {
-    sent_messages.mark_rendered_content_disparity(13, true);
-    assert.deepEqual(sent_messages.send_times_data[13].data.rendered_content_disparity, true);
-}());
-
 (function test_report_as_received() {
-    var msg = {
-        id: 12,
-        sent_by_me: true,
-    };
     var set_timeout_called = false;
     global.patch_builtin('setTimeout', function (func, delay) {
         assert.equal(delay, 0);
@@ -310,14 +301,13 @@ people.add(bob);
         assert(payload.data.locally_echoed);
         assert(!payload.data.rendered_content_disparity);
     };
-    sent_messages.report_as_received(msg);
+    sent_messages.report_as_received(12);
     assert.equal(typeof(data.received), 'object');
     assert.equal(typeof(data.displayed), 'object');
     assert(set_timeout_called);
 
     delete sent_messages.send_times_data[13];
-    msg.id = 13;
-    sent_messages.report_as_received(msg);
+    sent_messages.report_as_received(13);
     data = sent_messages.get_message_state(13).data;
     assert.equal(typeof(data.received), 'object');
     assert.equal(typeof(data.displayed), 'object');
@@ -1243,27 +1233,6 @@ function test_with_mock_socket(test_params) {
         assert(!$("#preview_message_area").visible());
         assert($("#markdown_preview").visible());
     }());
-
-    (function test_message_id_changed_document() {
-        sent_messages.initialize();
-        var handler = $(document).get_on_handler('message_id_changed');
-        sent_messages.send_times_data = {
-            1031: {
-                data: 'Test data!',
-            },
-        };
-        event.old_id = 1031;
-        event.new_id = 1045;
-
-        handler(event);
-
-        var send_times_data = {
-            1045: {
-                data: 'Test data!',
-            },
-        };
-        assert.deepEqual(sent_messages.send_times_data, send_times_data);
-    }());
 }());
 
 (function test_upload_started() {
diff --git a/static/js/compose.js b/static/js/compose.js
index c8ac14d48b..17e9a9638d 100644
--- a/static/js/compose.js
+++ b/static/js/compose.js
@@ -216,11 +216,15 @@ exports.send_message_success = function (local_id, message_id, locally_echoed) {
 };
 
 exports.transmit_message = function (request, on_success, error) {
-    request.client_message_id = sent_messages.get_new_client_message_id({
+    var client_message_id = sent_messages.get_new_client_message_id({
         local_id: request.local_id,
     });
 
-    sent_messages.clear(request.id);
+    // The host will attach this to message events, and it will allow
+    // us to match up the right messages to this request.
+    request.client_message_id = client_message_id;
+
+    sent_messages.clear(client_message_id);
 
     var local_id = request.local_id;
     var start_time = new Date();
@@ -231,11 +235,13 @@ exports.transmit_message = function (request, on_success, error) {
         // box and turning off spinners and reifying locally echoed messages.
         on_success(data);
 
-        var message_id = data.id;
-
         // Once everything is reified, get ready to report times to the server.
-        sent_messages.process_success(message_id, start_time, locally_echoed);
-        sent_messages.set_timer_for_restarting_event_loop(message_id);
+        sent_messages.process_success({
+            client_message_id: client_message_id,
+            start: start_time,
+            locally_echoed: locally_echoed,
+        });
+        sent_messages.set_timer_for_restarting_event_loop(client_message_id);
     }
 
     if (page_params.use_websockets) {
diff --git a/static/js/echo.js b/static/js/echo.js
index 8e0b508649..4fed65bcbe 100644
--- a/static/js/echo.js
+++ b/static/js/echo.js
@@ -173,11 +173,14 @@ exports.process_from_server = function process_from_server(messages) {
             if (client_message.content !== message.content) {
                 client_message.content = message.content;
                 updated = true;
-                sent_messages.mark_rendered_content_disparity(message.id, true);
+                sent_messages.mark_rendered_content_disparity({
+                    client_message_id: message.client_message_id,
+                    changed: true,
+                });
             }
             msgs_to_rerender.push(client_message);
             locally_processed_ids.push(client_message.id);
-            sent_messages.report_as_received(client_message);
+            sent_messages.report_as_received(message.client_message_id);
             delete waiting_for_ack[client_message.id];
             return false;
         }
diff --git a/static/js/message_util.js b/static/js/message_util.js
index a5afb654a0..a8cfd34835 100644
--- a/static/js/message_util.js
+++ b/static/js/message_util.js
@@ -23,7 +23,7 @@ exports.add_messages = function add_messages(messages, msg_list, opts) {
     if (msg_list === home_msg_list && opts.messages_are_new) {
         _.each(messages, function (message) {
             if (message.local_id === undefined) {
-                sent_messages.report_as_received(message);
+                sent_messages.report_as_received(message.client_message_id);
             }
         });
     }
diff --git a/static/js/sent_messages.js b/static/js/sent_messages.js
index d6a98bf03e..27ea179d39 100644
--- a/static/js/sent_messages.js
+++ b/static/js/sent_messages.js
@@ -100,42 +100,42 @@ exports.message_state = function () {
     return self;
 };
 
-exports.get_message_state = function (message_id) {
-    if (exports.send_times_data[message_id] === undefined) {
-        exports.send_times_data[message_id] = exports.message_state();
+exports.get_message_state = function (client_message_id) {
+    if (exports.send_times_data[client_message_id] === undefined) {
+        exports.send_times_data[client_message_id] = exports.message_state();
     }
 
-    return exports.send_times_data[message_id];
+    return exports.send_times_data[client_message_id];
 };
 
 
-function mark_end_to_end_receive_time(message_id) {
-    var state = exports.get_message_state(message_id);
+function mark_end_to_end_receive_time(client_message_id) {
+    var state = exports.get_message_state(client_message_id);
     state.mark_received();
 }
 
-function mark_end_to_end_display_time(message_id) {
-    var state = exports.get_message_state(message_id);
+function mark_end_to_end_display_time(client_message_id) {
+    var state = exports.get_message_state(client_message_id);
     state.mark_displayed();
 }
 
-exports.mark_rendered_content_disparity = function (message_id, changed) {
-    var state = exports.get_message_state(message_id);
-    state.mark_disparity(changed);
+exports.mark_rendered_content_disparity = function (opts) {
+    var state = exports.get_message_state(opts.client_message_id);
+    state.mark_disparity(opts.changed);
 };
 
-exports.report_as_received = function report_as_received(message) {
-    if (message.sent_by_me) {
-        mark_end_to_end_receive_time(message.id);
+exports.report_as_received = function report_as_received(client_message_id) {
+    if (client_message_id) {
+        mark_end_to_end_receive_time(client_message_id);
         setTimeout(function () {
-            mark_end_to_end_display_time(message.id);
+            mark_end_to_end_display_time(client_message_id);
         }, 0);
     }
 };
 
-exports.process_success = function (message_id, start_time, locally_echoed) {
+exports.process_success = function (opts) {
     var send_finished = new Date();
-    var send_time = (send_finished - start_time);
+    var send_time = (send_finished - opts.start);
     if (feature_flags.log_send_times) {
         blueslip.log("send time: " + send_time);
     }
@@ -143,36 +143,28 @@ exports.process_success = function (message_id, start_time, locally_echoed) {
         exports.send_times_log.push(send_time);
     }
 
-    var state = exports.get_message_state(message_id);
+    var state = exports.get_message_state(opts.client_message_id);
     state.process_success({
-        start: start_time,
+        start: opts.start,
         send_finished: send_finished,
-        locally_echoed: locally_echoed,
+        locally_echoed: opts.locally_echoed,
     });
 };
 
-exports.set_timer_for_restarting_event_loop = function (message_id) {
+exports.set_timer_for_restarting_event_loop = function (client_message_id) {
     setTimeout(function () {
-        if (!exports.send_times_data[message_id].was_received()) {
-            blueslip.log("Restarting get_events due to delayed receipt of sent message " + message_id);
+        if (!exports.send_times_data[client_message_id].was_received()) {
+            blueslip.log("Restarting get_events due to delayed receipt of sent message " + client_message_id);
             server_events.restart_get_events();
         }
     }, 5000);
 };
 
-exports.clear = function (message_id) {
-    delete exports.send_times_data[message_id];
+exports.clear = function (client_message_id) {
+    delete exports.send_times_data[client_message_id];
 };
 
 exports.initialize = function () {
-    $(document).on('message_id_changed', function (event) {
-        if (exports.send_times_data[event.old_id] !== undefined) {
-            var value = exports.send_times_data[event.old_id];
-            exports.send_times_data[event.new_id] = value;
-            delete exports.send_times_data[event.old_id];
-        }
-    });
-
     exports.reset_id_state();
 };
 
diff --git a/static/js/server_events.js b/static/js/server_events.js
index 642b7dbad3..3358b315b2 100644
--- a/static/js/server_events.js
+++ b/static/js/server_events.js
@@ -74,6 +74,7 @@ function get_events_success(events) {
             msg.local_id = sent_messages.get_local_id({
                 client_message_id: event.client_message_id,
             });
+            msg.client_message_id = event.client_message_id;
 
             messages.push(msg);
             break;