diff --git a/include/BufferedMsg.hpp b/include/BufferedMsg.hpp
index 59353331..e2baea1a 100644
--- a/include/BufferedMsg.hpp
+++ b/include/BufferedMsg.hpp
@@ -16,8 +16,9 @@ namespace fabomatic
   {
     std::string mqtt_message;
     std::string mqtt_topic;
+    bool wait_for_answer;
     BufferedMsg() = default;
-    BufferedMsg(const std::string &message, const std::string &topic) : mqtt_message(message), mqtt_topic(topic){};
+    BufferedMsg(const std::string &message, const std::string &topic, bool wait) : mqtt_message(message), mqtt_topic(topic), wait_for_answer{wait} {};
     BufferedMsg(const BufferedMsg &source) = default;
     BufferedMsg(BufferedMsg &source) = default;
   };
@@ -28,10 +29,11 @@ namespace fabomatic
     std::deque<BufferedMsg> msg_queue;
     bool has_changed{true};
     static constexpr auto MAGIC_NUMBER = 1;
+    static constexpr auto MAX_MESSAGES = 40;
 
   public:
-    auto push_back(const std::string &message, const std::string &topic) -> void;
-    auto push_front(const std::string &message, const std::string &topic) -> void;
+    auto push_back(const std::string &message, const std::string &topic, bool wait) -> void;
+    auto push_front(const std::string &message, const std::string &topic, bool wait) -> void;
     auto getMessage() -> const BufferedMsg;
     auto count() const -> size_t;
     auto toJson(JsonDocument &doc, const std::string &element_name) const -> void;
@@ -46,13 +48,14 @@ namespace fabomatic
   private:
     std::string_view mqtt_value;
     std::string_view mqtt_topic;
+    bool wait_for_answer;
 
   public:
     BufferedQuery() = delete;
-    constexpr BufferedQuery(const std::string_view &value, const std::string_view &topic) : mqtt_value(value), mqtt_topic(topic){};
+    constexpr BufferedQuery(const std::string_view &value, const std::string_view &topic, bool wait) : mqtt_value(value), mqtt_topic(topic), wait_for_answer{wait} {};
 
     [[nodiscard]] auto payload() const -> const std::string override { return std::string(mqtt_value); };
-    [[nodiscard]] auto waitForReply() const -> bool override { return false; };
+    [[nodiscard]] auto waitForReply() const -> bool override { return wait_for_answer; };
     [[nodiscard]] auto buffered() const -> bool override { return false; };
     [[nodiscard]] auto topic() const -> std::string { return std::string(mqtt_topic); };
   };
diff --git a/src/BufferedMsg.cpp b/src/BufferedMsg.cpp
index d875ccee..4dbc2895 100644
--- a/src/BufferedMsg.cpp
+++ b/src/BufferedMsg.cpp
@@ -6,24 +6,34 @@
 namespace fabomatic
 {
 
-  auto Buffer::push_back(const std::string &message, const std::string &topic) -> void
+  auto Buffer::push_back(const std::string &message, const std::string &topic, bool wait) -> void
   {
     if constexpr (conf::debug::ENABLE_BUFFERING)
     {
-      BufferedMsg msg{message, topic};
+      BufferedMsg msg{message, topic, wait};
       msg_queue.push_back(msg);
+      if (msg_queue.size() > MAX_MESSAGES)
+      {
+        msg_queue.pop_front();
+        ESP_LOGW(TAG, "Removing first message from the buffer");
+      }
       has_changed = true;
 
       ESP_LOGI(TAG, "Buffered %s on %s, %lu messages queued", message.c_str(), topic.c_str(), msg_queue.size());
     }
   }
 
-  auto Buffer::push_front(const std::string &message, const std::string &topic) -> void
+  auto Buffer::push_front(const std::string &message, const std::string &topic, bool wait) -> void
   {
     if constexpr (conf::debug::ENABLE_BUFFERING)
     {
-      BufferedMsg msg{message, topic};
+      BufferedMsg msg{message, topic, wait};
       msg_queue.push_front(msg);
+      if (msg_queue.size() > MAX_MESSAGES)
+      {
+        msg_queue.pop_back();
+        ESP_LOGW(TAG, "Removing last message from the buffer");
+      }
       has_changed = true;
 
       ESP_LOGI(TAG, "Buffered %s on %s, %lu messages queued", message.c_str(), topic.c_str(), msg_queue.size());
@@ -35,7 +45,7 @@ namespace fabomatic
     if (msg_queue.size() == 0)
     {
       ESP_LOGE(TAG, "Calling getMessage() on empty queue!");
-      return {"", ""};
+      return {"", "", false};
     }
 
     auto elem = msg_queue.front();
@@ -59,8 +69,9 @@ namespace fabomatic
     for (auto elem = msg_queue.begin(); elem != msg_queue.end(); elem++)
     {
       auto obj_msg = json_elem.createNestedObject();
-      obj_msg["topic"] = elem->mqtt_topic;
-      obj_msg["message"] = elem->mqtt_message;
+      obj_msg["tp"] = elem->mqtt_topic;
+      obj_msg["msg"] = elem->mqtt_message;
+      obj_msg["wait"] = elem->wait_for_answer;
     }
   }
 
@@ -78,8 +89,9 @@ namespace fabomatic
 
     for (const auto &elem : json_obj["messages"].as<JsonArray>())
     {
-      buff.push_back(elem["message"].as<std::string>(),
-                     elem["topic"].as<std::string>());
+      buff.push_back(elem["msg"].as<std::string>(),
+                     elem["tp"].as<std::string>(),
+                     elem["wait"].as<bool>());
     }
 
     ESP_LOGD(TAG, "Buffer::fromJsonElement() : data loaded successfully");
diff --git a/src/FabBackend.cpp b/src/FabBackend.cpp
index dd8e11cf..b092b0ca 100644
--- a/src/FabBackend.cpp
+++ b/src/FabBackend.cpp
@@ -93,7 +93,7 @@ namespace fabomatic
 
     if (query.buffered())
     {
-      buffer.push_back(query.payload(), topic);
+      buffer.push_back(query.payload(), topic, query.waitForReply());
     }
     return false;
   }
@@ -391,7 +391,22 @@ namespace fabomatic
     static_assert(std::is_base_of<ServerMQTT::Response, RespT>::value, "RespT must inherit from Response");
     QueryT query{args...};
 
-    if (isOnline())
+    auto nb_tries = 0;
+    while (isOnline() && hasBufferedMsg() && !transmitBuffer() && nb_tries < 3)
+    {
+      // To preserve chronological order, we cannot send new messages until the old ones have been sent.
+      ESP_LOGW(TAG, "Online with pending messages that could not be transmitted, retrying...");
+
+      Tasks::delay(250ms);
+
+      if (!isOnline())
+      {
+        connect();
+      }
+      nb_tries++;
+    }
+
+    if (isOnline() && !hasBufferedMsg())
     {
       if (publishWithReply(query))
       {
@@ -413,7 +428,7 @@ namespace fabomatic
 
     if (query.buffered())
     {
-      buffer.push_back(query.payload(), topic);
+      buffer.push_back(query.payload(), topic, query.waitForReply());
     }
 
     return std::make_unique<RespT>(false);
@@ -432,7 +447,22 @@ namespace fabomatic
     static_assert(std::is_base_of<ServerMQTT::Query, QueryT>::value, "QueryT must inherit from Query");
     QueryT query{args...};
 
-    if (isOnline())
+    auto nb_tries = 0;
+    while (isOnline() && hasBufferedMsg() && !transmitBuffer() && nb_tries < 3)
+    {
+      // To preserve chronological order, we cannot send new messages until the old ones have been sent.
+      ESP_LOGW(TAG, "Online with pending messages that could not be transmitted, retrying...");
+
+      Tasks::delay(250ms);
+
+      if (!isOnline())
+      {
+        connect();
+      }
+      nb_tries++;
+    }
+
+    if (isOnline() && !hasBufferedMsg())
     {
       if (publish(query))
       {
@@ -447,7 +477,7 @@ namespace fabomatic
 
     if (query.buffered())
     {
-      buffer.push_back(query.payload(), topic);
+      buffer.push_back(query.payload(), topic, query.waitForReply());
     }
     return false;
   }
@@ -548,15 +578,31 @@ namespace fabomatic
   {
     while (hasBufferedMsg() && isOnline())
     {
+      ESP_LOGD(TAG, "Retransmitting buffered messages...");
       const auto &msg = buffer.getMessage();
-      const BufferedQuery bq{msg.mqtt_message, msg.mqtt_topic};
-      if (!publish(bq))
+      const BufferedQuery bq{msg.mqtt_message, msg.mqtt_topic, msg.wait_for_answer};
+      if (bq.waitForReply())
       {
-        // Will try again
-        buffer.push_front(msg.mqtt_message, msg.mqtt_topic);
-        break;
+        if (!publishWithReply(bq))
+        {
+          ESP_LOGW(TAG, "Retransmitting buffered message failed!");
+          // Will try again
+          buffer.push_front(msg.mqtt_message, msg.mqtt_topic, msg.wait_for_answer);
+          break;
+        }
+      }
+      else
+      {
+        if (!publish(bq))
+        {
+          // Will try again
+          ESP_LOGW(TAG, "Retransmitting buffered message failed!");
+          buffer.push_front(msg.mqtt_message, msg.mqtt_topic, msg.wait_for_answer);
+          break;
+        }
       }
     }
+    last_reply = "";
     return !hasBufferedMsg();
   }