diff --git a/LXMF/LXMRouter.py b/LXMF/LXMRouter.py
index 64677a8..5c71f93 100644
--- a/LXMF/LXMRouter.py
+++ b/LXMF/LXMRouter.py
@@ -1234,6 +1234,30 @@ class LXMRouter:
         else:
             return False
     
+    def cancel_outbound(self, message_id):
+        try:
+            lxmessage = None
+            for lxm in self.pending_outbound:
+                if lxm.message_id == message_id:
+                    lxmessage = lxm
+
+            if message_id in self.pending_deferred_stamps:
+                RNS.log(f"Cancelling deferred stamp generation for {lxmessage}", RNS.LOG_DEBUG)
+
+            if lxmessage != None:
+                lxmessage.state = LXMessage.CANCELLED
+                if lxmessage in self.pending_outbound:
+                    RNS.log(f"Cancelling {lxmessage} in outbound queue", RNS.LOG_DEBUG)
+                    if lxmessage.representation == LXMessage.RESOURCE:
+                        if lxmessage.resource_representation != None:
+                            lxmessage.resource_representation.cancel()
+
+                    self.process_outbound()
+
+        except Exception as e:
+            RNS.log(f"An error occurred while cancelling {lxmessage}: {e}", RNS.LOG_ERROR)
+            RNS.trace_exception(e)
+
     def handle_outbound(self, lxmessage):
         destination_hash = lxmessage.get_destination().hash
 
@@ -1780,10 +1804,15 @@ class LXMRouter:
                             self.pending_outbound.append(selected_lxm)
                             RNS.log(f"Stamp generation completed for {selected_lxm}", RNS.LOG_DEBUG)
                         else:
-                            RNS.log(f"Deferred stamp generation did not succeed. Failing {selected_lxm}.", RNS.LOG_ERROR)
-                            selected_lxm.stamp_generation_failed = True
-                            self.pending_deferred_stamps.pop(selected_message_id)
-                            self.fail_message(selected_lxm)
+                            if selected_lxm.state == LXMessage.CANCELLED:
+                                RNS.log(f"Message cancelled during deferred stamp generation for {selected_lxm}.", RNS.LOG_ERROR)
+                                selected_lxm.stamp_generation_failed = True
+                                self.pending_deferred_stamps.pop(selected_message_id)
+                            else:
+                                RNS.log(f"Deferred stamp generation did not succeed. Failing {selected_lxm}.", RNS.LOG_ERROR)
+                                selected_lxm.stamp_generation_failed = True
+                                self.pending_deferred_stamps.pop(selected_message_id)
+                                self.fail_message(selected_lxm)
 
 
     def process_outbound(self, sender = None):
@@ -1820,8 +1849,14 @@ class LXMRouter:
                 RNS.log("Propagation has occurred for "+str(lxmessage)+", removing from outbound queue", RNS.LOG_DEBUG)
                 self.pending_outbound.remove(lxmessage)
 
+            elif lxmessage.state == LXMessage.CANCELLED:
+                RNS.log("Cancellation requested for "+str(lxmessage)+", removing from outbound queue", RNS.LOG_DEBUG)
+                self.pending_outbound.remove(lxmessage)
+                if lxmessage.failed_callback != None and callable(lxmessage.failed_callback):
+                    lxmessage.failed_callback(lxmessage)
+
             else:
-                RNS.log("Starting outbound processing for "+str(lxmessage)+" to "+RNS.prettyhexrep(lxmessage.get_destination().hash), RNS.LOG_DEBUG)
+                RNS.log("Outbound processing for "+str(lxmessage)+" to "+RNS.prettyhexrep(lxmessage.get_destination().hash), RNS.LOG_DEBUG)
 
                 if lxmessage.progress == None or lxmessage.progress < 0.01:
                     lxmessage.progress = 0.01
diff --git a/LXMF/LXMessage.py b/LXMF/LXMessage.py
index 253085b..316e798 100644
--- a/LXMF/LXMessage.py
+++ b/LXMF/LXMessage.py
@@ -16,8 +16,9 @@ class LXMessage:
     SENDING            = 0x02
     SENT               = 0x04
     DELIVERED          = 0x08
+    CANCELLED          = 0xFE
     FAILED             = 0xFF
-    states             = [GENERATING, OUTBOUND, SENDING, SENT, DELIVERED, FAILED]
+    states             = [GENERATING, OUTBOUND, SENDING, SENT, DELIVERED, CANCELLED, FAILED]
 
     UNKNOWN            = 0x00
     PACKET             = 0x01
@@ -564,22 +565,24 @@ class LXMessage:
         if resource.status == RNS.Resource.COMPLETE:
             self.__mark_delivered()
         else:
-            resource.link.teardown()
-            self.state = LXMessage.OUTBOUND
+            if self.state != LXMessage.CANCELLED:
+                resource.link.teardown()
+                self.state = LXMessage.OUTBOUND
 
     def __propagation_resource_concluded(self, resource):
         if resource.status == RNS.Resource.COMPLETE:
             self.__mark_propagated()
         else:
-            resource.link.teardown()
-            self.state = LXMessage.OUTBOUND
+            if self.state != LXMessage.CANCELLED:
+                resource.link.teardown()
+                self.state = LXMessage.OUTBOUND
 
     def __link_packet_timed_out(self, packet_receipt):
-        if packet_receipt:
-            packet_receipt.destination.teardown()
-    
-        self.state = LXMessage.OUTBOUND
-
+        if self.state != LXMessage.CANCELLED:
+            if packet_receipt:
+                packet_receipt.destination.teardown()
+        
+            self.state = LXMessage.OUTBOUND
 
     def __update_transfer_progress(self, resource):
         self.progress = 0.10 + (resource.get_progress()*0.90)