diff --git a/js/Notify.js b/js/Notify.js
index b4d026f..93ffecf 100644
--- a/js/Notify.js
+++ b/js/Notify.js
@@ -1,6 +1,12 @@
+const MAX_QUEUE_SIZE = 30
 
 var Notify = function (message, limit=false, groups=false) {
 
+  // Remove messages from older versions
+  if(Memory.__notify) {
+    delete Memory.__notify
+  }
+
   if(!groups) {
     groups = ['default']
   }
@@ -35,16 +41,39 @@ var Notify = function (message, limit=false, groups=false) {
   return 0
 }
 
+let reset = Game.time
+let num = 0
+let shardid = ''
+if(Game.shard && Game.shard.name) {
+  const matches = Game.shard.name.match(/\d+$/);
+  if (matches) {
+    shardid = parseInt(matches[0]).toString(36);
+  }
+}
+
+Notify.getUUID = function () {
+  if (reset !== Game.time) {
+    reset = Game.time
+    num = 0
+  }
+  num++
+  return shardid + Game.time.toString(36) + num.toString(36).leftPad(3, '0')
+}
+
 
 Notify.queueMessage = function (message, groups) {
-  if(!Memory.__notify) {
-    Memory.__notify = []
+  if(!Memory.__notify_v2) {
+    Memory.__notify_v2 = {}
+  }
+  if (Memory.__notify_v2.length >= MAX_QUEUE_SIZE) {
+    return false
   }
-  Memory.__notify.push({
+  const id = Notify.getUUID()
+  Memory.__notify_v2[id] = {
     'message': message,
     'groups': groups,
     'tick': Game.time
-  })
+  }
 }
 
 // Clean up history instead of leaving old messages around
@@ -53,15 +82,24 @@ Notify.cleanHistory = function (limit) {
     limit = 20000
   }
 
-  if(!Memory.__notify_history) {
-    return
+  // Clear any already sent messages
+  if(Memory.__notify_v2) {
+    var ids = Object.keys(Memory.__notify_v2)
+    for(var id of ids) {
+      if(typeof Memory.__notify_v2[id] !== 'Object') {
+        delete Memory.__notify_v2[id]
+      }
+    }
   }
 
-  var messages = Object.keys(Memory.__notify_history)
-  for(var i in messages) {
-    var message = messages[i]
-    if(Memory.__notify_history[message] < Game.time - limit) {
-      delete Memory.__notify_history[message]
+  // Clear expired historical messages.
+  if(Memory.__notify_history) {
+    var messages = Object.keys(Memory.__notify_history)
+    for(var i in messages) {
+      var message = messages[i]
+      if(Memory.__notify_history[message] < Game.time - limit) {
+        delete Memory.__notify_history[message]
+      }
     }
   }
 }
diff --git a/screeps_notify/clear_notifications.js b/screeps_notify/clear_notifications.js
deleted file mode 100644
index a4ccd23..0000000
--- a/screeps_notify/clear_notifications.js
+++ /dev/null
@@ -1 +0,0 @@
-if(typeof limit == 'undefined') var limit = 0; Memory.__notify = _.filter(Memory.__notify, function(notification){ return notification.tick > this.limit }.bind({'limit':limit}))
\ No newline at end of file
diff --git a/screeps_notify/notify.py b/screeps_notify/notify.py
index 533641b..fe7a2e8 100755
--- a/screeps_notify/notify.py
+++ b/screeps_notify/notify.py
@@ -31,18 +31,23 @@ def getScreepsConnection():
 
 def getNotifications(shard):
     sconn = getScreepsConnection()
-    notifications = sconn.memory(path='__notify', shard=shard)
+    notifications = sconn.memory(path='__notify_v2', shard=shard)
     if 'data' not in notifications:
         return False
-    return notifications['data']
+    notificationMap = notifications['data']
+    messages = []
+    for messageId, message in notificationMap.items():
+        if isinstance(message, dict):
+            message['messageId'] = messageId
+            message['shard'] = shard
+            messages.append(message)
+    return messages
 
 
-def clearNotifications(tick=0, shard='shard0'):
+def clearNotification(messageId, shard='shard0'):
     print 'clearing sent messages'
     sconn = getScreepsConnection()
-    javascript_clear = 'var limit=' + str(tick) + ';'
-    javascript_clear += "if(typeof limit == 'undefined') var limit = 0; Memory.__notify = _.filter(Memory.__notify, function(notification){ return notification.tick > this.limit }.bind({'limit':limit}))"
-    sconn.console(javascript_clear, shard=shard)
+    sconn.set_memory('__notify_v2.%s' % messageId, None, shard)
 
 
 class App():
@@ -63,17 +68,14 @@ def run(self):
             if not notifications or len(notifications) <= 0:
                 print 'No notifications to send.'
                 continue
-            limit = 0
+
             print 'Sending notifications.'
             for notification in notifications:
-                if notification['tick'] > limit:
-                    limit = notification['tick']
-
+                msgid = notification['messageId']
                 if 'groups' in notification:
                     groups = notification['groups']
                 else:
                     groups = ['default']
-
                 services = config.getServicesFromGroups(groups)
                 for service in services:
                     try:
@@ -81,8 +83,8 @@ def run(self):
                         driver.sendMessage(notification['message'], shard)
                     except:
                         traceback.print_exc()
+                clearNotification(msgid, shard)
 
-            clearNotifications(limit, shard)
 
 def lambda_handler(event,context):
     app = App()