diff --git a/include/AlertFifoQueue.h b/include/AlertFifoQueue.h
index f4635e3ef8..1272b56b36 100644
--- a/include/AlertFifoQueue.h
+++ b/include/AlertFifoQueue.h
@@ -24,11 +24,6 @@
 
 #include "ntop_includes.h"
 
-typedef struct {
-  AlertLevel level;
-  char *alert;
-} AlertFifoItem;
-
 class AlertFifoQueue : public FifoQueue<AlertFifoItem> {
  public:
   AlertFifoQueue(u_int32_t queue_size) : FifoQueue<AlertFifoItem>(queue_size) {}
@@ -47,7 +42,7 @@ class AlertFifoQueue : public FifoQueue<AlertFifoItem> {
     m.lock(__FILE__, __LINE__);
 
     if(q.empty()) {
-      rv.level = alert_level_none;
+      rv.alert_severity = alert_level_none;
       rv.alert = NULL;
     } else {
       rv = q.front();
diff --git a/include/Ntop.h b/include/Ntop.h
index 91736aadd1..c3d6fb51eb 100644
--- a/include/Ntop.h
+++ b/include/Ntop.h
@@ -469,8 +469,8 @@ class Ntop {
   inline void setnDPICleanupNeeded(bool needed)           { ndpi_cleanup_needed = needed; }
   inline FifoSerializerQueue* getInternalAlertsQueue()    { return(internal_alerts_queue);  }
   void lua_alert_queues_stats(lua_State* vm);
-  bool  recipient_enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const char * const notification);
-  char* recipient_dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio);
+  bool recipient_enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const AlertFifoItem* const notification);
+  bool recipient_dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio, AlertFifoItem *notification);
   void recipient_stats(u_int16_t recipient_id, lua_State* vm);
   void recipient_delete(u_int16_t recipient_id);
   void recipient_register(u_int16_t recipient_id);
diff --git a/include/RecipientQueues.h b/include/RecipientQueues.h
index af384617c0..a3b8be421c 100644
--- a/include/RecipientQueues.h
+++ b/include/RecipientQueues.h
@@ -42,10 +42,11 @@ class RecipientQueues {
   /**
   * @brief Dequeues a notification from a `recipient_id` queue, given a certain priority
   * @param prio The priority of the notification
+  * @param notification The dequeued notification
   *
-  * @return A pointer to a notification string, or NULL if there was no notification in the queue. The pointer MUST be `free`d after use
+  * @return Boolean, true if the dequeue was successful and `notification` is populated correctly, false otherwise
   */
-  char *dequeue(RecipientNotificationPriority prio);
+  bool dequeue(RecipientNotificationPriority prio, AlertFifoItem *notification);
   /**
   * @brief Enqueues a notification to a `recipient_id` queue, depending on the priority
   * @param recipient_id An integer recipient identifier
@@ -54,7 +55,7 @@ class RecipientQueues {
   *
   * @return True if the enqueue succeeded, false otherwise
   */
-  bool enqueue(RecipientNotificationPriority prio, const char * const notification);
+  bool enqueue(RecipientNotificationPriority prio, const AlertFifoItem* const notification);
   /**
    * @brief Returns queue status (drops and uses)
    * @param vm A Lua VM instance
diff --git a/include/Recipients.h b/include/Recipients.h
index aa39342766..5e124feafc 100644
--- a/include/Recipients.h
+++ b/include/Recipients.h
@@ -37,20 +37,20 @@ class Recipients {
   /**
   * @brief Dequeues a notification from a `recipient_id` queue, given a certain priority
   * @param recipient_id An integer recipient identifier
-  * @param prio The priority of the notification
+  * @param notification The dequeued notification
   *
-  * @return A pointer to a notification string, or NULL if there was no notification in the queue. The pointer MUST be `free`d after use
+  * @return Boolean, true if the dequeue was successful and `notification` is populated correctly, false otherwise
   */
-  char *dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio);
+  bool dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio, AlertFifoItem *notification);
   /**
   * @brief Enqueues a notification to a `recipient_id` queue, depending on the priority
   * @param recipient_id An integer recipient identifier
   * @param prio The priority of the notification
-  * @param notification A string containing the notification
+  * @param notification The notification to be enqueued
   *
   * @return True if the enqueue succeeded, false otherwise
   */
-  bool enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const char * const notification);
+  bool enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const AlertFifoItem* const notification);
   /**
   * @brief Registers a recipient identified with `recipient_id` so its notification can be enqueued/dequeued
   * @param recipient_id An integer recipient identifier
diff --git a/include/ntop_typedefs.h b/include/ntop_typedefs.h
index ca4d1c04e5..4fc4e7ff9d 100644
--- a/include/ntop_typedefs.h
+++ b/include/ntop_typedefs.h
@@ -204,6 +204,12 @@ typedef enum {
   IPV6 = 6
 } IPVersion;
 
+/* Used to queue/dequeue elements in recipient queues via AlertFifoQueue.h */
+typedef struct {
+  AlertLevel alert_severity;
+  char *alert;
+} AlertFifoItem;
+
 struct zmq_msg_hdr_v0 {
   char url[32];
   u_int32_t version;
diff --git a/scripts/lua/modules/alert_consts.lua b/scripts/lua/modules/alert_consts.lua
index faf5ea1709..dbe61a8fc5 100644
--- a/scripts/lua/modules/alert_consts.lua
+++ b/scripts/lua/modules/alert_consts.lua
@@ -541,7 +541,7 @@ end
 -- ##############################################
 
 function alert_consts.alertLevelToSyslogLevel(v)
-  return alert_severities[v].syslog_severity
+   return alert_severities[alert_consts.alertSeverityRaw(v)].syslog_severity
 end
 
 -- ################################################################################
diff --git a/scripts/lua/modules/notifications/recipients.lua b/scripts/lua/modules/notifications/recipients.lua
index c4042db449..fd95bcffa5 100644
--- a/scripts/lua/modules/notifications/recipients.lua
+++ b/scripts/lua/modules/notifications/recipients.lua
@@ -644,7 +644,7 @@ function recipients.dispatch_notification(notification, current_script)
 	 local is_high_priority = is_notification_high_priority(notification)
 
 	 for _, recipient_id in pairs(recipients) do
-	    ntop.recipient_enqueue(recipient_id, is_high_priority, json_notification)
+	    ntop.recipient_enqueue(recipient_id, is_high_priority, json_notification, notification.alert_severity)
 	 end
       end
    else
diff --git a/scripts/plugins/endpoints/discord_alert_endpoint/alert_endpoints/discord.lua b/scripts/plugins/endpoints/discord_alert_endpoint/alert_endpoints/discord.lua
index 03598b1e7c..5b647ba451 100644
--- a/scripts/plugins/endpoints/discord_alert_endpoint/alert_endpoints/discord.lua
+++ b/scripts/plugins/endpoints/discord_alert_endpoint/alert_endpoints/discord.lua
@@ -143,7 +143,7 @@ function discord.dequeueRecipientAlerts(recipient, budget, high_priority)
     for i=1, max_alerts_per_request do
        local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
        if notification then 
-	  notifications[#notifications + 1] = notification
+	  notifications[#notifications + 1] = notification.alert
        else
 	  break
        end
diff --git a/scripts/plugins/endpoints/email_alert_endpoint/alert_endpoints/email.lua b/scripts/plugins/endpoints/email_alert_endpoint/alert_endpoints/email.lua
index c16d65a938..290b73e60f 100644
--- a/scripts/plugins/endpoints/email_alert_endpoint/alert_endpoints/email.lua
+++ b/scripts/plugins/endpoints/email_alert_endpoint/alert_endpoints/email.lua
@@ -131,7 +131,7 @@ function email.dequeueRecipientAlerts(recipient, budget, high_priority)
     for i = 1, MAX_ALERTS_PER_EMAIL do
        local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
        if notification then 
-	  notifications[#notifications + 1] = notification
+	  notifications[#notifications + 1] = notification.alert
        else
 	  break
        end
diff --git a/scripts/plugins/endpoints/shell_alert_endpoint/alert_endpoints/shell.lua b/scripts/plugins/endpoints/shell_alert_endpoint/alert_endpoints/shell.lua
index 6886dfd813..e55aa75381 100644
--- a/scripts/plugins/endpoints/shell_alert_endpoint/alert_endpoints/shell.lua
+++ b/scripts/plugins/endpoints/shell_alert_endpoint/alert_endpoints/shell.lua
@@ -164,7 +164,7 @@ function shell.dequeueRecipientAlerts(recipient, budget, high_priority)
     for i = 1, MAX_ALERTS_PER_REQUEST do
        local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
        if notification then
-	  notifications[#notifications + 1] = notification
+	  notifications[#notifications + 1] = notification.alert
        else
 	  break
        end
diff --git a/scripts/plugins/endpoints/slack_alert_endpoint/alert_endpoints/slack.lua b/scripts/plugins/endpoints/slack_alert_endpoint/alert_endpoints/slack.lua
index 3a9ea00393..1508755a24 100644
--- a/scripts/plugins/endpoints/slack_alert_endpoint/alert_endpoints/slack.lua
+++ b/scripts/plugins/endpoints/slack_alert_endpoint/alert_endpoints/slack.lua
@@ -88,7 +88,7 @@ function slack.dequeueRecipientAlerts(recipient, budget, high_priority)
    for i = 1, budget do
       local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
       if notification then 
-	 notifications[#notifications + 1] = notification
+	 notifications[#notifications + 1] = notification.alert
       else
 	 break
       end
diff --git a/scripts/plugins/endpoints/sqlite_alert_endpoint/alert_endpoints/sqlite.lua b/scripts/plugins/endpoints/sqlite_alert_endpoint/alert_endpoints/sqlite.lua
index 516bbf3dbd..937f505361 100644
--- a/scripts/plugins/endpoints/sqlite_alert_endpoint/alert_endpoints/sqlite.lua
+++ b/scripts/plugins/endpoints/sqlite_alert_endpoint/alert_endpoints/sqlite.lua
@@ -55,7 +55,7 @@ function sqlite.dequeueRecipientAlerts(recipient, budget, high_priority)
      for i=1, budget do
        local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
        if notification then 
-	  notifications[#notifications + 1] = notification
+	  notifications[#notifications + 1] = notification.alert
        else
 	  break
        end
diff --git a/scripts/plugins/endpoints/syslog_alert_endpoint/alert_endpoints/syslog.lua b/scripts/plugins/endpoints/syslog_alert_endpoint/alert_endpoints/syslog.lua
index a0cb578872..d9af74e054 100644
--- a/scripts/plugins/endpoints/syslog_alert_endpoint/alert_endpoints/syslog.lua
+++ b/scripts/plugins/endpoints/syslog_alert_endpoint/alert_endpoints/syslog.lua
@@ -79,24 +79,20 @@ function syslog.sendMessage(settings, notif, severity, syslog_format)
    local msg
 
    if syslog_format and syslog_format == "json" then
-      -- send out the json message but prepare a nice
-      -- message
-      notif.message  = alert_utils.formatAlertNotification(notif, {
-         nohtml = true,
-	 show_severity = false,
-	 show_entity = false})
-      msg = json.encode(notif)
+      -- Send it plain, notif is already a json-encoded string
+      -- so for efficiency, no decoding is done
+      msg = notif
    elseif syslog_format and syslog_format == "ecs" then
      if ntop.isEnterpriseM() then
         package.path = dirs.installdir .. "/pro/scripts/lua/modules/?.lua;" .. package.path
         local ecs_format = require "ecs_format"
-        msg = json.encode(ecs_format.format(notif))
+        msg = json.encode(ecs_format.format(json.decode(notif)))
      else
         return false
      end
    else -- syslog_format == "plaintext"
       -- prepare a plaintext message
-      msg = alert_utils.formatAlertNotification(notif, {
+      msg = alert_utils.formatAlertNotification(json.decode(notif), {
          nohtml = true,
 	 show_severity = true,
 	 show_entity = true})
@@ -147,27 +143,9 @@ function syslog.dequeueRecipientAlerts(recipient, budget, high_priority)
       return {success = true, more_available = false}
    end
 
-   -- Separate by severity and channel
-   local alerts_by_types = {}
-
-   for _, json_message in ipairs(notifications) do
-      local notif = json.decode(json_message)
-      if notif.alert_entity then
-         alerts_by_types[notif.alert_entity] = alerts_by_types[notif.alert_entity] or {}
-         alerts_by_types[notif.alert_entity][notif.alert_severity] = alerts_by_types[notif.alert_entity][notif.alert_severity] or {}
-         table.insert(alerts_by_types[notif.alert_entity][notif.alert_severity], notif)
-      end
-   end
-
-   for _, by_severity in pairs(alerts_by_types) do
-      for severity, sev_notifications in pairs(by_severity) do
-        severity = alert_consts.alertSeverityRaw(severity)
-
-	 -- Most recent notifications first
-	 for _, notif in pairsByValues(sev_notifications, alert_utils.notification_timestamp_rev) do
-            syslog.sendMessage(settings, notif, severity, recipient.endpoint_conf.syslog_alert_format)
-	 end
-      end
+   -- Most recent notifications first
+   for _, notification in ipairs(notifications) do
+      syslog.sendMessage(settings, notification.alert, notification.alert_severity, recipient.endpoint_conf.syslog_alert_format)
    end
 
    return {success = true,  more_available = true}
diff --git a/scripts/plugins/endpoints/telegram_alert_endpoint/alert_endpoints/telegram.lua b/scripts/plugins/endpoints/telegram_alert_endpoint/alert_endpoints/telegram.lua
index 362e81a963..82a7a8fb07 100644
--- a/scripts/plugins/endpoints/telegram_alert_endpoint/alert_endpoints/telegram.lua
+++ b/scripts/plugins/endpoints/telegram_alert_endpoint/alert_endpoints/telegram.lua
@@ -132,7 +132,7 @@ function telegram.dequeueRecipientAlerts(recipient, budget, high_priority)
     for i=1, max_alerts_per_request do
        local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
        if notification then 
-	  notifications[#notifications + 1] = notification
+	  notifications[#notifications + 1] = notification.alert
        else
 	  break
        end
diff --git a/scripts/plugins/endpoints/webhook_alert_endpoint/alert_endpoints/webhook.lua b/scripts/plugins/endpoints/webhook_alert_endpoint/alert_endpoints/webhook.lua
index 5d3f2dba45..9ca229f232 100644
--- a/scripts/plugins/endpoints/webhook_alert_endpoint/alert_endpoints/webhook.lua
+++ b/scripts/plugins/endpoints/webhook_alert_endpoint/alert_endpoints/webhook.lua
@@ -105,7 +105,7 @@ function webhook.dequeueRecipientAlerts(recipient, budget, high_priority)
     for i = 1, MAX_ALERTS_PER_REQUEST do
        local notification = ntop.recipient_dequeue(recipient.recipient_id, high_priority)
        if notification then 
-	  notifications[#notifications + 1] = notification
+	  notifications[#notifications + 1] = notification.alert
        else
 	  break
        end
diff --git a/src/LuaEngineNtop.cpp b/src/LuaEngineNtop.cpp
index b91830fed4..0f3fb99690 100644
--- a/src/LuaEngineNtop.cpp
+++ b/src/LuaEngineNtop.cpp
@@ -5409,6 +5409,8 @@ static int ntop_recipient_enqueue(lua_State* vm) {
   bool high_priority;
   const char *alert;
   bool rv = false;
+  AlertFifoItem notification;
+  AlertLevel alert_severity;
 
   if(ntop_lua_check(vm, __FUNCTION__, 1, LUA_TNUMBER) != CONST_LUA_OK) return(CONST_LUA_ERROR);
   recipient_id = lua_tointeger(vm, 1);
@@ -5419,9 +5421,16 @@ static int ntop_recipient_enqueue(lua_State* vm) {
   if(ntop_lua_check(vm, __FUNCTION__, 3, LUA_TSTRING) != CONST_LUA_OK) return(CONST_LUA_ERROR);
   alert = lua_tostring(vm, 3);
 
-  rv = ntop->recipient_enqueue(recipient_id,
-			       high_priority ? recipient_notification_priority_high : recipient_notification_priority_low,
-			       alert);
+  if(ntop_lua_check(vm, __FUNCTION__, 4, LUA_TNUMBER) != CONST_LUA_OK) return(CONST_LUA_ERROR);
+  alert_severity = (AlertLevel)lua_tonumber(vm, 4);
+
+  if((notification.alert = strdup(alert))) {
+    notification.alert_severity = alert_severity;
+
+    rv = ntop->recipient_enqueue(recipient_id,
+				 high_priority ? recipient_notification_priority_high : recipient_notification_priority_low,
+				 &notification);
+  }
 
   if(!rv) {
     NetworkInterface *iface = getCurrentInterface(vm);
@@ -5431,6 +5440,9 @@ static int ntop_recipient_enqueue(lua_State* vm) {
       if(ctx->threaded_activity_stats)
 	ctx->threaded_activity_stats->setAlertsDrops();
     }
+
+    if(notification.alert)
+      free(notification.alert);
   }
 
   lua_pushboolean(vm, rv);
@@ -5442,7 +5454,8 @@ static int ntop_recipient_enqueue(lua_State* vm) {
 static int ntop_recipient_dequeue(lua_State* vm) {
   u_int16_t recipient_id;
   bool high_priority;
-  char *alert;
+  AlertFifoItem notification;
+  bool res;
 
   if(ntop_lua_check(vm, __FUNCTION__, 1, LUA_TNUMBER) != CONST_LUA_OK) return(CONST_LUA_ERROR);
   recipient_id = lua_tointeger(vm, 1);
@@ -5450,12 +5463,17 @@ static int ntop_recipient_dequeue(lua_State* vm) {
   if(ntop_lua_check(vm, __FUNCTION__, 2, LUA_TBOOLEAN) != CONST_LUA_OK) return(CONST_LUA_ERROR);
   high_priority = lua_toboolean(vm, 2);
 
-  alert = ntop->recipient_dequeue(recipient_id,
-				  high_priority ? recipient_notification_priority_high : recipient_notification_priority_low);
+  res = ntop->recipient_dequeue(recipient_id,
+				high_priority ? recipient_notification_priority_high : recipient_notification_priority_low,
+				  &notification);
 
-  if(alert) {
-    lua_pushstring(vm, alert);
-    free(alert);
+  if(res && notification.alert) {
+    lua_newtable(vm);
+
+    lua_push_str_table_entry(vm, "alert", notification.alert);
+    lua_push_uint64_table_entry(vm, "alert_severity", notification.alert_severity);
+
+    free(notification.alert);
   } else
     lua_pushnil(vm);
 
diff --git a/src/Ntop.cpp b/src/Ntop.cpp
index a2484b6a8d..b63b8b0faf 100644
--- a/src/Ntop.cpp
+++ b/src/Ntop.cpp
@@ -982,14 +982,14 @@ void Ntop::lua_alert_queues_stats(lua_State* vm) {
 
 /* ******************************************* */
 
-bool Ntop::recipient_enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const char * const notification) {
+bool Ntop::recipient_enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const AlertFifoItem* const notification) {
   return recipients.enqueue(recipient_id, prio, notification);
 }
 
 /* ******************************************* */
 
-char* Ntop::recipient_dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio) {
-  return recipients.dequeue(recipient_id, prio);
+bool Ntop::recipient_dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio, AlertFifoItem *notification) {
+  return recipients.dequeue(recipient_id, prio, notification);
 }
 
 /* ******************************************* */
diff --git a/src/RecipientQueues.cpp b/src/RecipientQueues.cpp
index 19922bae52..516786d5ad 100644
--- a/src/RecipientQueues.cpp
+++ b/src/RecipientQueues.cpp
@@ -40,49 +40,39 @@ RecipientQueues::~RecipientQueues() {
 
 /* *************************************** */
 
-char* RecipientQueues::dequeue(RecipientNotificationPriority prio) {
-  AlertFifoItem res;
+bool RecipientQueues::dequeue(RecipientNotificationPriority prio, AlertFifoItem *notification) {
+  if(prio >= RECIPIENT_NOTIFICATION_MAX_NUM_PRIORITIES
+     || !queues_by_prio[prio]
+     || !notification)
+    return false;
 
-  if(prio >= RECIPIENT_NOTIFICATION_MAX_NUM_PRIORITIES || 
-     !queues_by_prio[prio])
-    return NULL;
+  *notification = queues_by_prio[prio]->dequeue();
 
-  res = queues_by_prio[prio]->dequeue();
-
-  if(res.alert)
+  if(notification->alert) {
     last_use = time(NULL);
+    return true;
+  }
 
-  /* TODO return severity level */
-
-  return res.alert;
+  return false;
 }
 
 /* *************************************** */
 
-bool RecipientQueues::enqueue(RecipientNotificationPriority prio, const char * const notification) {
+bool RecipientQueues::enqueue(RecipientNotificationPriority prio, const AlertFifoItem* const notification) {
   bool res = false;
-  AlertFifoItem item;
 
-  if(prio >= RECIPIENT_NOTIFICATION_MAX_NUM_PRIORITIES ||
-     (!queues_by_prio[prio] && 
-      !(queues_by_prio[prio] = new (nothrow) AlertFifoQueue(ALERTS_NOTIFICATIONS_QUEUE_SIZE)))) {
+  if(prio >= RECIPIENT_NOTIFICATION_MAX_NUM_PRIORITIES
+     || !notification
+     || !notification->alert
+     || (!queues_by_prio[prio] &&
+	 !(queues_by_prio[prio] = new (nothrow) AlertFifoQueue(ALERTS_NOTIFICATIONS_QUEUE_SIZE)))) {
     /* Queue not available */
     drops_by_prio[prio]++;
     return false;
   }
 
-  /* Qnqueue the notification */
-
-  item.level = alert_level_none; /* TODO set severity level */
-  item.alert = strdup(notification);
-
-  if(item.alert) {
-
-    res = queues_by_prio[prio]->enqueue(item);
-
-    if (!res)
-      free(item.alert);
-  }
+  /* Enqueue the notification */
+  res = queues_by_prio[prio]->enqueue(*notification);
 
   if(!res)
     drops_by_prio[prio]++;
diff --git a/src/Recipients.cpp b/src/Recipients.cpp
index aa141fc3c9..bfd62e93bc 100644
--- a/src/Recipients.cpp
+++ b/src/Recipients.cpp
@@ -38,11 +38,12 @@ Recipients::~Recipients() {
 
 /* *************************************** */
 
-char* Recipients::dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio) {
-  char * res = NULL;
+bool Recipients::dequeue(u_int16_t recipient_id, RecipientNotificationPriority prio, AlertFifoItem *notification) {
+  bool res = false;
 
-  if(recipient_id >= MAX_NUM_RECIPIENTS)
-    return NULL;
+  if(recipient_id >= MAX_NUM_RECIPIENTS
+     || !notification)
+    return false;
 
   m.lock(__FILE__, __LINE__);
 
@@ -50,7 +51,7 @@ char* Recipients::dequeue(u_int16_t recipient_id, RecipientNotificationPriority
     /*
       Dequeue the notification for a given priority
     */
-    res = recipient_queues[recipient_id]->dequeue(prio);
+    res = recipient_queues[recipient_id]->dequeue(prio, notification);
   }
 
   m.unlock(__FILE__, __LINE__);
@@ -60,10 +61,11 @@ char* Recipients::dequeue(u_int16_t recipient_id, RecipientNotificationPriority
 
 /* *************************************** */
 
-bool Recipients::enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const char * const notification) {
+bool Recipients::enqueue(u_int16_t recipient_id, RecipientNotificationPriority prio, const AlertFifoItem* const notification) {
   bool res = false;
 
-  if(recipient_id >= MAX_NUM_RECIPIENTS)
+  if(recipient_id >= MAX_NUM_RECIPIENTS
+     || !notification)
     return false;
 
   m.lock(__FILE__, __LINE__);