diff --git a/jasmin/managers/dlr.py b/jasmin/managers/dlr.py
index a8561e91..6ea2ff8c 100644
--- a/jasmin/managers/dlr.py
+++ b/jasmin/managers/dlr.py
@@ -4,6 +4,7 @@
 
 from twisted.internet import defer
 from twisted.internet import reactor
+from twisted.internet.error import AlreadyCalled, AlreadyCancelled
 from txamqp.queue import Closed
 from txredisapi import ConnectionError
 from smpp.pdu.pdu_types import RegisteredDeliveryReceipt
@@ -71,6 +72,22 @@ def subscribe(self):
         yield self.amqpBroker.chan.basic_consume(queue=queueName, no_ack=False, consumer_tag=consumerTag)
         self.amqpBroker.client.queue(consumerTag).addCallback(self.setup_callbacks)
 
+    def clearRequeueTimer(self, msgid):
+        if msgid in self.requeue_timers:
+            try:
+                self.requeue_timers[msgid].cancel()
+            except AlreadyCalled or AlreadyCancelled:
+                pass
+            del self.requeue_timers[msgid]
+
+    def clearRequeueTimers(self):
+        for msgid, timer in list(self.requeue_timers.items()):
+            try:
+                timer.cancel()
+            except AlreadyCalled or AlreadyCancelled:
+                pass
+            del self.requeue_timers[msgid]
+
     @defer.inlineCallbacks
     def rejectAndRequeueMessage(self, message, delay=True):
         msgid = message.content.properties['message-id']
@@ -79,21 +96,25 @@ def rejectAndRequeueMessage(self, message, delay=True):
             self.log.debug("Requeuing Content[%s] with delay: %s seconds",
                            msgid, self.config.dlr_lookup_retry_delay)
 
-            # Requeue the message with a delay
-            timer = reactor.callLater(self.config.dlr_lookup_retry_delay,
-                                      self.rejectMessage,
-                                      message=message,
-                                      requeue=1)
-
-            # If any, clear timer before setting a new one
+            # If any, reset timer
             if msgid in self.requeue_timers:
                 timer = self.requeue_timers[msgid]
-                if timer.active():
-                    timer.cancel()
-                del self.requeue_timers[msgid]
+                try:
+                    timer.reset(self.config.dlr_lookup_retry_delay)
+                except AlreadyCalled:
+                    # noting to do here, already rejected
+                    pass
+                except AlreadyCancelled:
+                    # noting to do here, already rejected
+                    pass
+            else:
+                # Set new timer
+                timer = reactor.callLater(self.config.dlr_lookup_retry_delay,
+                                          self.rejectMessage,
+                                          message=message,
+                                          requeue=1)
+                self.requeue_timers[msgid] = timer
 
-            # Set new timer
-            self.requeue_timers[msgid] = timer
             defer.returnValue(timer)
         else:
             self.log.debug("Requeuing Content[%s] without delay", msgid)
@@ -104,6 +125,11 @@ def rejectMessage(self, message, requeue=0):
         if requeue == 0 and message.content.properties['message-id'] in self.lookup_retrials:
             # Remove retrial tracker
             del self.lookup_retrials[message.content.properties['message-id']]
+        
+        self.clearRequeueTimer(message.content.properties['message-id'])
+        if not self.amqpBroker.connected:
+            self.log.error("Cannot reject message, AMQP Broker is not connected !")
+            defer.returnValue(False)
 
         yield self.amqpBroker.chan.basic_reject(delivery_tag=message.delivery_tag, requeue=requeue)
 
@@ -113,6 +139,11 @@ def ackMessage(self, message):
         if message.content.properties['message-id'] in self.lookup_retrials:
             # Remove retrial tracker
             del self.lookup_retrials[message.content.properties['message-id']]
+        
+        self.clearRequeueTimer(message.content.properties['message-id'])
+        if not self.amqpBroker.connected:
+            self.log.error("Cannot ack message, AMQP Broker is not connected !")
+            defer.returnValue(False)
 
         yield self.amqpBroker.chan.basic_ack(message.delivery_tag)