diff --git a/services/tunnelbroker/src/cxx_bridge.rs b/services/tunnelbroker/src/cxx_bridge.rs
--- a/services/tunnelbroker/src/cxx_bridge.rs
+++ b/services/tunnelbroker/src/cxx_bridge.rs
@@ -40,6 +40,13 @@
     deviceOS: String,
     isOnline: bool,
   }
+  struct MessageItem {
+    messageID: String,
+    fromDeviceID: String,
+    toDeviceID: String,
+    payload: String,
+    blobHashes: String,
+  }
 
   unsafe extern "C++" {
     include!("tunnelbroker/src/libcpp/Tunnelbroker.h");
@@ -65,5 +72,7 @@
       sessionID: &str,
       newNotifToken: &str,
     ) -> Result<()>;
+    pub fn getMessagesFromDatabase(deviceID: &str) -> Result<Vec<MessageItem>>;
+    pub fn eraseMessagesFromAMQP(deviceID: &str) -> Result<()>;
   }
 }
diff --git a/services/tunnelbroker/src/libcpp/Tunnelbroker.h b/services/tunnelbroker/src/libcpp/Tunnelbroker.h
--- a/services/tunnelbroker/src/libcpp/Tunnelbroker.h
+++ b/services/tunnelbroker/src/libcpp/Tunnelbroker.h
@@ -18,3 +18,5 @@
 SessionItem getSessionItem(rust::Str sessionID);
 void updateSessionItemIsOnline(rust::Str sessionID, bool isOnline);
 void updateSessionItemDeviceToken(rust::Str sessionID, rust::Str newNotifToken);
+rust::Vec<MessageItem> getMessagesFromDatabase(rust::Str deviceID);
+void eraseMessagesFromAMQP(rust::Str deviceID);
diff --git a/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp b/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
--- a/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
+++ b/services/tunnelbroker/src/libcpp/Tunnelbroker.cpp
@@ -4,6 +4,7 @@
 #include "ConfigManager.h"
 #include "CryptoTools.h"
 #include "DatabaseManager.h"
+#include "DeliveryBroker.h"
 #include "GlobalTools.h"
 #include "Tools.h"
 
@@ -183,3 +184,24 @@
       .updateSessionItemDeviceToken(
           std::string{sessionID}, std::string{newNotifToken});
 }
+
+rust::Vec<MessageItem> getMessagesFromDatabase(rust::Str deviceID) {
+  std::vector<std::shared_ptr<comm::network::database::MessageItem>>
+      messagesFromDatabase =
+          comm::network::database::DatabaseManager::getInstance()
+              .findMessageItemsByReceiver(std::string{deviceID});
+  rust::Vec<MessageItem> result;
+  for (auto &messageFromDatabase : messagesFromDatabase) {
+    result.push_back(MessageItem{
+        .messageID = messageFromDatabase->getMessageID(),
+        .fromDeviceID = messageFromDatabase->getFromDeviceID(),
+        .payload = messageFromDatabase->getPayload(),
+        .blobHashes = messageFromDatabase->getBlobHashes(),
+    });
+  }
+  return result;
+}
+
+void eraseMessagesFromAMQP(rust::Str deviceID) {
+  comm::network::DeliveryBroker::getInstance().erase(std::string{deviceID});
+}
diff --git a/services/tunnelbroker/src/server/mod.rs b/services/tunnelbroker/src/server/mod.rs
--- a/services/tunnelbroker/src/server/mod.rs
+++ b/services/tunnelbroker/src/server/mod.rs
@@ -1,7 +1,8 @@
 use super::constants;
 use super::cxx_bridge::ffi::{
-  getSessionItem, newSessionHandler, sessionSignatureHandler,
-  updateSessionItemDeviceToken, updateSessionItemIsOnline, GRPCStatusCodes,
+  eraseMessagesFromAMQP, getMessagesFromDatabase, getSessionItem,
+  newSessionHandler, sessionSignatureHandler, updateSessionItemDeviceToken,
+  updateSessionItemIsOnline, GRPCStatusCodes,
 };
 use anyhow::Result;
 use futures::Stream;
@@ -151,6 +152,46 @@
       };
     }
 
+    // When a client connects to the bidirectional messages stream, first we check
+    // if there are undelivered messages in the database
+    let messages_from_database =
+      match getMessagesFromDatabase(&session_item.deviceID) {
+        Ok(messages) => messages,
+        Err(err) => return Err(Status::internal(err.what())),
+      };
+    if messages_from_database.len() > 0 {
+      if let Err(err) = eraseMessagesFromAMQP(&session_item.deviceID) {
+        return Err(Status::internal(err.what()));
+      };
+      let mut messages_to_response = vec![];
+      for message in &messages_from_database {
+        messages_to_response.push(tunnelbroker::MessageToClientStruct {
+          message_id: message.messageID.clone(),
+          from_device_id: message.fromDeviceID.clone(),
+          payload: message.payload.clone(),
+          blob_hashes: vec![message.blobHashes.clone()],
+        });
+      }
+      let result_from_writer = tx_writer(
+        &session_id,
+        &tx,
+        Ok(tunnelbroker::MessageToClient {
+          data: Some(tunnelbroker::message_to_client::Data::MessagesToDeliver(
+            tunnelbroker::MessagesToDeliver {
+              messages: messages_to_response,
+            },
+          )),
+        }),
+      );
+      if let Err(err) = result_from_writer.await {
+        debug!(
+          "Error while sending undelivered messages from database to the client: {}",
+          err
+        );
+        return Err(Status::aborted(err));
+      };
+    }
+
     // Spawning asynchronous Tokio task with the client pinging loop inside to
     // make sure that the client is online
     tokio::spawn({