diff --git a/.eslintrc.json b/.eslintrc.json
index 1334de11aa..849ef5b259 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -57,6 +57,7 @@
         "typing_events": false,
         "typing_data": false,
         "typing_status": false,
+        "sent_messages": false,
         "compose": false,
         "compose_actions": false,
         "compose_state": false,
diff --git a/frontend_tests/node_tests/compose.js b/frontend_tests/node_tests/compose.js
index 7c2034aee4..4a47c916c3 100644
--- a/frontend_tests/node_tests/compose.js
+++ b/frontend_tests/node_tests/compose.js
@@ -34,6 +34,11 @@ set_global('stream_edit', {});
 set_global('markdown', {});
 set_global('loading', {});
 
+set_global('sent_messages', {
+    start_tracking_message: noop,
+    report_server_ack: noop,
+});
+
 // Setting these up so that we can test that links to uploads within messages are
 // automatically converted to server relative links.
 global.document.location.protocol = 'https:';
@@ -261,72 +266,23 @@ people.add(bob);
     $("#send-status").show();
     $("#compose-send-button").attr('disabled', 'disabled');
     $("#sending-indicator").show();
-    var set_timeout_called = false;
-    global.patch_builtin('setTimeout', function (func, delay) {
-        assert.equal(delay, 5000);
-        func();
-        set_timeout_called = true;
-    });
-    var server_events_triggered;
-    global.server_events = {
-        restart_get_events: function () {
-            server_events_triggered = true;
-        },
-    };
+
     var reify_message_id_checked;
     echo.reify_message_id = function (local_id, message_id) {
         assert.equal(local_id, 1001);
         assert.equal(message_id, 12);
         reify_message_id_checked = true;
     };
-    var test_date = 'Wed Jun 28 2017 22:12:48 GMT+0000 (UTC)';
-    compose.send_message_success(1001, 12, new Date(test_date), false);
+
+    compose.send_message_success(1001, 12, false);
+
     assert.equal($("#new_message_content").val(), '');
     assert($("#new_message_content").is_focused());
     assert(!$("#send-status").visible());
     assert.equal($("#compose-send-button").prop('disabled'), false);
     assert(!$("#sending-indicator").visible());
-    assert.equal(_.keys(compose.send_times_data).length, 1);
-    assert.equal(compose.send_times_data[12].start.getTime(), new Date(test_date).getTime());
-    assert(!compose.send_times_data[12].locally_echoed);
+
     assert(reify_message_id_checked);
-    assert(server_events_triggered);
-    assert(set_timeout_called);
-}());
-
-(function test_mark_rendered_content_disparity() {
-    compose.mark_rendered_content_disparity(13, true);
-    assert.deepEqual(compose.send_times_data[13], { 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);
-        func();
-        set_timeout_called = true;
-    });
-    compose.send_times_data[12].locally_echoed = true;
-    channel.post = function (payload) {
-        assert.equal(payload.url, '/json/report_send_time');
-        assert.equal(typeof(payload.data.time), 'string');
-        assert(payload.data.locally_echoed);
-        assert(!payload.data.rendered_content_disparity);
-    };
-    compose.report_as_received(msg);
-    assert.equal(typeof(compose.send_times_data[12].received), 'object');
-    assert.equal(typeof(compose.send_times_data[12].displayed), 'object');
-    assert(set_timeout_called);
-
-    delete compose.send_times_data[13];
-    msg.id = 13;
-    compose.report_as_received(msg);
-    assert.equal(typeof(compose.send_times_data[13].received), 'object');
-    assert.equal(typeof(compose.send_times_data[13].displayed), 'object');
 }());
 
 (function test_send_message() {
@@ -337,7 +293,6 @@ people.add(bob);
         stub_state.local_id_counter = 0;
         stub_state.send_msg_ajax_post_called = 0;
         stub_state.get_events_running_called = 0;
-        stub_state.server_events_triggered = 0;
         stub_state.reify_message_id_checked = 0;
         return stub_state;
     }
@@ -346,9 +301,6 @@ people.add(bob);
         func();
     });
     global.server_events = {
-        restart_get_events: function () {
-            stub_state.server_events_triggered += 1;
-        },
         assert_get_events_running: function () {
             stub_state.get_events_running_called += 1;
         },
@@ -392,7 +344,7 @@ people.add(bob);
             assert.equal(typeof(message_id), 'number');
             stub_state.reify_message_id_checked += 1;
         };
-        compose.send_times_data = {};
+
         // Setting message content with a host server link and we will assert
         // later that this has been converted to a relative link.
         $("#new_message_content").val('[foobar]' +
@@ -409,10 +361,8 @@ people.add(bob);
             get_events_running_called: 1,
             reify_message_id_checked: 1,
             send_msg_ajax_post_called: 1,
-            server_events_triggered: 1,
         };
         assert.deepEqual(stub_state, state);
-        assert.equal(_.keys(compose.send_times_data).length, 1);
         assert.equal($("#new_message_content").val(), '');
         assert($("#new_message_content").is_focused());
         assert(!$("#send-status").visible());
@@ -444,10 +394,8 @@ people.add(bob);
             get_events_running_called: 1,
             reify_message_id_checked: 0,
             send_msg_ajax_post_called: 1,
-            server_events_triggered: 0,
         };
         assert.deepEqual(stub_state, state);
-        assert.equal(_.keys(compose.send_times_data).length, 1);
         assert(server_error_triggered);
         assert(reload_initiate_triggered);
     }());
@@ -485,10 +433,8 @@ people.add(bob);
             get_events_running_called: 1,
             reify_message_id_checked: 0,
             send_msg_ajax_post_called: 1,
-            server_events_triggered: 0,
         };
         assert.deepEqual(stub_state, state);
-        assert.equal(_.keys(compose.send_times_data).length, 1);
         assert(server_error_triggered);
         assert(!reload_initiate_triggered);
         assert(xhr_error_msg_checked);
@@ -511,6 +457,10 @@ people.add(bob);
             return;
         };
 
+        sent_messages.get_new_local_id = function () {
+            return 'loc-55';
+        };
+
         compose.send_message();
 
         var state = {
@@ -518,10 +468,8 @@ people.add(bob);
             get_events_running_called: 1,
             reify_message_id_checked: 0,
             send_msg_ajax_post_called: 1,
-            server_events_triggered: 0,
         };
         assert.deepEqual(stub_state, state);
-        assert.equal(_.keys(compose.send_times_data).length, 1);
         assert(server_error_triggered);
         assert(!reload_initiate_triggered);
         assert(xhr_error_msg_checked);
@@ -792,9 +740,10 @@ function test_with_mock_socket(test_params) {
     // socket_user_agent field will be added.
     var request = {foo: 'bar'};
 
-    // Our success function gets passed all the way through to
-    // socket.send, so we can just use a stub to test that.
-    var success = 'success-function-stub';
+    var success_func_checked = false;
+    var success = function () {
+        success_func_checked = true;
+    };
 
     // Our error function gets wrapped, so we set up a real
     // function to test the wrapping mechanism.
@@ -818,8 +767,8 @@ function test_with_mock_socket(test_params) {
                 socket_user_agent: 'unittest_transmit_message',
             });
 
-            // Our success function never gets wrapped.
-            assert.equal(send_args.success, success);
+            send_args.success({});
+            assert(success_func_checked);
 
             // Our error function does get wrapped, so we test by
             // using socket.send's error callback, which should
@@ -1258,25 +1207,6 @@ function test_with_mock_socket(test_params) {
         assert($("#markdown_preview").visible());
     }());
 
-    (function test_message_id_changed_document() {
-        var handler = $(document).get_on_handler('message_id_changed');
-        compose.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(compose.send_times_data, send_times_data);
-    }());
 }());
 
 (function test_upload_started() {
diff --git a/static/js/compose.js b/static/js/compose.js
index 067c63c5c3..a61581f38d 100644
--- a/static/js/compose.js
+++ b/static/js/compose.js
@@ -179,20 +179,6 @@ function send_message_ajax(request, success, error) {
     });
 }
 
-function report_send_time(send_time, receive_time, display_time, locally_echoed, rendered_changed) {
-    var data = {time: send_time.toString(),
-                received: receive_time.toString(),
-                displayed: display_time.toString(),
-                locally_echoed: locally_echoed};
-    if (locally_echoed) {
-        data.rendered_content_disparity = rendered_changed;
-    }
-    channel.post({
-        url: '/json/report_send_time',
-        data: data,
-    });
-}
-
 var socket;
 if (page_params.use_websockets) {
     socket = new Socket("/sockjs");
@@ -211,61 +197,6 @@ function send_message_socket(request, success, error) {
     });
 }
 
-exports.send_times_data = {};
-function maybe_report_send_times(message_id) {
-    var data = exports.send_times_data[message_id];
-    if (data.send_finished === undefined || data.received === undefined ||
-        data.displayed === undefined) {
-        // We report the data once we have both the send and receive times
-        return;
-    }
-    report_send_time(data.send_finished - data.start,
-                     data.received - data.start,
-                     data.displayed - data.start,
-                     data.locally_echoed,
-                     data.rendered_content_disparity || false);
-}
-
-function mark_end_to_end_receive_time(message_id) {
-    if (exports.send_times_data[message_id] === undefined) {
-        exports.send_times_data[message_id] = {};
-    }
-    exports.send_times_data[message_id].received = new Date();
-    maybe_report_send_times(message_id);
-}
-
-function mark_end_to_end_display_time(message_id) {
-    exports.send_times_data[message_id].displayed = new Date();
-    maybe_report_send_times(message_id);
-}
-
-exports.mark_rendered_content_disparity = function (message_id, changed) {
-    if (exports.send_times_data[message_id] === undefined) {
-        exports.send_times_data[message_id] = {};
-    }
-    exports.send_times_data[message_id].rendered_content_disparity = changed;
-};
-
-exports.report_as_received = function report_as_received(message) {
-    if (message.sent_by_me) {
-        mark_end_to_end_receive_time(message.id);
-        setTimeout(function () {
-            mark_end_to_end_display_time(message.id);
-        }, 0);
-    }
-};
-
-function process_send_time(message_id, start_time, locally_echoed) {
-    var send_finished = new Date();
-    if (exports.send_times_data[message_id] === undefined) {
-        exports.send_times_data[message_id] = {};
-    }
-    exports.send_times_data[message_id].start = start_time;
-    exports.send_times_data[message_id].send_finished = send_finished;
-    exports.send_times_data[message_id].locally_echoed  = locally_echoed;
-    maybe_report_send_times(message_id);
-}
-
 function clear_compose_box() {
     $("#new_message_content").val('').focus();
     drafts.delete_draft_after_send();
@@ -276,25 +207,25 @@ function clear_compose_box() {
     resize.resize_bottom_whitespace();
 }
 
-exports.send_message_success = function (local_id, message_id, start_time, locally_echoed) {
+exports.send_message_success = function (local_id, message_id, locally_echoed) {
     if (!locally_echoed) {
         clear_compose_box();
     }
 
-    process_send_time(message_id, start_time, locally_echoed);
-
     echo.reify_message_id(local_id, message_id);
-
-    setTimeout(function () {
-        if (exports.send_times_data[message_id].received === undefined) {
-            blueslip.log("Restarting get_events due to delayed receipt of sent message " + message_id);
-            server_events.restart_get_events();
-        }
-    }, 5000);
 };
 
-exports.transmit_message = function (request, success, error) {
-    delete exports.send_times_data[request.id];
+exports.transmit_message = function (request, on_success, error) {
+
+    function success(data) {
+        // Call back to our callers to do things like closing the compose
+        // box and turning off spinners and reifying locally echoed messages.
+        on_success(data);
+
+        // Once everything is done, get ready to report times to the server.
+        sent_messages.report_server_ack(request.local_id);
+    }
+
     if (page_params.use_websockets) {
         send_message_socket(request, success, error);
     } else {
@@ -313,27 +244,41 @@ exports.send_message = function send_message(request) {
         request.to = JSON.stringify([request.to]);
     }
 
-    var start_time = new Date();
     var local_id;
+    var locally_echoed;
 
     local_id = echo.try_deliver_locally(request);
-    if (local_id !== undefined) {
-        // We delivered this message locally
-        request.local_id = local_id;
+    if (local_id) {
+        // We are rendering this message locally with an id
+        // like 92l99.01 that corresponds to a reasonable
+        // approximation of the id we'll get from the server
+        // in terms of sorting messages.
+        locally_echoed = true;
+    } else {
+        // We are not rendering this message locally, but we
+        // track the message's life cycle with an id like
+        // loc-1, loc-2, loc-3,etc.
+        locally_echoed = false;
+        local_id = sent_messages.get_new_local_id();
     }
 
-    var locally_echoed = local_id !== undefined;
+    request.local_id = local_id;
+
+    sent_messages.start_tracking_message({
+        local_id: local_id,
+        locally_echoed: locally_echoed,
+    });
 
     request.locally_echoed = locally_echoed;
 
     function success(data) {
-        exports.send_message_success(local_id, data.id, start_time, locally_echoed);
+        exports.send_message_success(local_id, data.id, locally_echoed);
     }
 
     function error(response) {
         // If we're not local echo'ing messages, or if this message was not
         // locally echoed, show error in compose box
-        if (!request.locally_echoed) {
+        if (!locally_echoed) {
             compose_error(response, $('#new_message_content'));
             return;
         }
@@ -893,15 +838,6 @@ exports.initialize = function () {
             compose_actions.start("stream", {});
         }
     }
-
-    $(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];
-            delete exports.send_times_data[event.old_id];
-            exports.send_times_data[event.new_id] =
-                _.extend({}, exports.send_times_data[event.old_id], value);
-        }
-    });
 };
 
 return exports;
diff --git a/static/js/echo.js b/static/js/echo.js
index 170772e0d3..b3e9909a68 100644
--- a/static/js/echo.js
+++ b/static/js/echo.js
@@ -9,26 +9,34 @@ function resend_message(message, row) {
     message.content = message.raw_content;
     var retry_spinner = row.find('.refresh-failed-message');
     retry_spinner.toggleClass('rotating', true);
+
     // Always re-set queue_id if we've gotten a new one
     // since the time when the message object was initially created
     message.queue_id = page_params.queue_id;
-    var start_time = new Date();
-    compose.transmit_message(message, function success(data) {
-        retry_spinner.toggleClass('rotating', false);
 
+    var local_id = message.local_id;
+
+    function on_success(data) {
         var message_id = data.id;
+        var locally_echoed = true;
 
         retry_spinner.toggleClass('rotating', false);
-        compose.send_message_success(message.local_id, message_id, start_time, true);
+
+        compose.send_message_success(local_id, message_id, locally_echoed);
 
         // Resend succeeded, so mark as no longer failed
         message_store.get(message_id).failed_request = false;
         ui.show_failed_message_success(message_id);
-    }, function error(response) {
-        exports.message_send_error(message.local_id, response);
+    }
+
+    function on_error(response) {
+        exports.message_send_error(local_id, response);
         retry_spinner.toggleClass('rotating', false);
         blueslip.log("Manual resend of message failed");
-    });
+    }
+
+    sent_messages.start_resend(local_id);
+    compose.transmit_message(message, on_success, on_error);
 }
 
 function truncate_precision(float) {
@@ -205,18 +213,18 @@ exports.process_from_server = function process_from_server(messages) {
     var msgs_to_rerender = [];
     messages = _.filter(messages, function (message) {
         // In case we get the sent message before we get the send ACK, reify here
-        exports.reify_message_id(message.local_id, message.id);
 
         var client_message = waiting_for_ack[message.local_id];
         if (client_message !== undefined) {
+            exports.reify_message_id(message.local_id, message.id);
+
             if (client_message.content !== message.content) {
                 client_message.content = message.content;
                 updated = true;
-                compose.mark_rendered_content_disparity(message.id, true);
+                sent_messages.mark_disparity(message.local_id);
             }
             msgs_to_rerender.push(client_message);
             locally_processed_ids.push(client_message.id);
-            compose.report_as_received(client_message);
             delete waiting_for_ack[client_message.id];
             return false;
         }
diff --git a/static/js/message_util.js b/static/js/message_util.js
index 16c74fc7af..6ff722e26d 100644
--- a/static/js/message_util.js
+++ b/static/js/message_util.js
@@ -19,14 +19,6 @@ exports.add_messages = function add_messages(messages, msg_list, opts) {
     $('#first_run_message').remove();
 
     msg_list.add_messages(messages, opts);
-
-    if (msg_list === home_msg_list && opts.messages_are_new) {
-        _.each(messages, function (message) {
-            if (message.local_id === undefined) {
-                compose.report_as_received(message);
-            }
-        });
-    }
 };
 
 
diff --git a/static/js/sent_messages.js b/static/js/sent_messages.js
new file mode 100644
index 0000000000..82d7de922f
--- /dev/null
+++ b/static/js/sent_messages.js
@@ -0,0 +1,184 @@
+var sent_messages = (function () {
+
+var exports = {};
+
+exports.messages = {};
+
+exports.reset_id_state = function () {
+    exports.next_local_id = 0;
+};
+
+exports.get_new_local_id = function () {
+    exports.next_local_id += 1;
+    var local_id = exports.next_local_id;
+    return 'loc-' + local_id.toString();
+};
+
+function report_send_time(send_time, receive_time,
+                          locally_echoed, rendered_changed) {
+    var data = {
+        time: send_time.toString(),
+        received: receive_time.toString(),
+        locally_echoed: locally_echoed,
+    };
+
+    if (locally_echoed) {
+        data.rendered_content_disparity = rendered_changed;
+    }
+
+    channel.post({
+        url: '/json/report_send_time',
+        data: data,
+    });
+}
+
+exports.start_tracking_message = function (opts) {
+    var local_id = opts.local_id;
+
+    if (!opts.local_id) {
+        blueslip.error('You must supply a local_id');
+        return;
+    }
+
+    if (exports.messages[local_id] !== undefined) {
+        blueslip.error('We are re-using a local_id');
+        return;
+    }
+
+    var state = exports.message_state(opts);
+
+    exports.messages[local_id] = state;
+};
+
+exports.message_state = function (opts) {
+    var self = {};
+    self.data = {};
+
+    self.data.start = new Date();
+
+    self.data.local_id = opts.local_id;
+    self.data.locally_echoed = opts.locally_echoed;
+
+
+    self.data.received = undefined;
+    self.data.send_finished = undefined;
+    self.data.rendered_content_disparity = false;
+
+    self.start_resend = function () {
+        self.data.start = new Date();
+        self.data.received = undefined;
+        self.data.send_finished = undefined;
+        self.data.rendered_content_disparity = false;
+    };
+
+    self.maybe_restart_event_loop = function () {
+        if (self.data.received) {
+            // We got our event, no need to do anything
+            return;
+        }
+
+        blueslip.log("Restarting get_events due to " +
+                     "delayed receipt of sent message " +
+                     self.data.local_id);
+
+        server_events.restart_get_events();
+    };
+
+    self.maybe_report_send_times = function () {
+        if (!self.ready()) {
+            return;
+        }
+        var data = self.data;
+        report_send_time(data.send_finished - data.start,
+                         data.received - data.start,
+                         data.locally_echoed,
+                         data.rendered_content_disparity);
+    };
+
+    self.report_event_received = function () {
+        self.data.received = new Date();
+        self.maybe_report_send_times();
+    };
+
+    self.mark_disparity = function () {
+        self.data.rendered_content_disparity = true;
+    };
+
+    self.report_server_ack = function () {
+        self.data.send_finished = new Date();
+        self.maybe_report_send_times();
+
+        // We only start our timer for events coming in here,
+        // since it's plausible the server rejected our message,
+        // or took a while to process it, but there is nothing
+        // wrong with our event loop.
+
+        if (!self.data.received) {
+            setTimeout(self.maybe_restart_event_loop, 5000);
+        }
+    };
+
+    self.ready = function () {
+        return (self.data.send_finished !== undefined) &&
+               (self.data.received !== undefined);
+    };
+
+    return self;
+};
+
+exports.get_message_state = function (local_id) {
+    var state = exports.messages[local_id];
+
+    if (!state) {
+        blueslip.warn('Unknown local_id: ' + local_id);
+    }
+
+    return state;
+};
+
+
+exports.mark_disparity = function (local_id) {
+    var state = exports.get_message_state(local_id);
+    if (!state) {
+        return;
+    }
+    state.mark_disparity();
+};
+
+exports.report_event_received = function (local_id) {
+    var state = exports.get_message_state(local_id);
+    if (!state) {
+        return;
+    }
+
+    state.report_event_received();
+};
+
+exports.start_resend = function (local_id) {
+    var state = exports.get_message_state(local_id);
+    if (!state) {
+        return;
+    }
+
+    state.start_resend();
+};
+
+exports.report_server_ack = function (local_id) {
+    var state = exports.get_message_state(local_id);
+    if (!state) {
+        return;
+    }
+
+    state.report_server_ack();
+};
+
+exports.initialize = function () {
+    exports.reset_id_state();
+};
+
+return exports;
+
+}());
+if (typeof module !== 'undefined') {
+    module.exports = sent_messages;
+}
diff --git a/static/js/server_events.js b/static/js/server_events.js
index ee3636adb9..150cc25eac 100644
--- a/static/js/server_events.js
+++ b/static/js/server_events.js
@@ -68,8 +68,9 @@ function get_events_success(events) {
         case 'message':
             var msg = event.message;
             msg.flags = event.flags;
-            if (event.local_message_id !== undefined) {
+            if (event.local_message_id) {
                 msg.local_id = event.local_message_id;
+                sent_messages.report_event_received(event.local_message_id);
             }
             messages.push(msg);
             break;
diff --git a/static/js/ui_init.js b/static/js/ui_init.js
index 9875f86989..15f86b22d9 100644
--- a/static/js/ui_init.js
+++ b/static/js/ui_init.js
@@ -267,6 +267,7 @@ $(function () {
     pm_list.initialize();
     stream_list.initialize();
     drafts.initialize();
+    sent_messages.initialize();
     compose.initialize();
 });
 
diff --git a/zproject/settings.py b/zproject/settings.py
index bc22b2969d..789530e5af 100644
--- a/zproject/settings.py
+++ b/zproject/settings.py
@@ -873,6 +873,7 @@ JS_SPECS = {
             'js/markdown.js',
             'js/echo.js',
             'js/socket.js',
+            'js/sent_messages.js',
             'js/compose_state.js',
             'js/compose_actions.js',
             'js/compose.js',