diff --git a/Cargo.lock b/Cargo.lock
index bdbc538..026e141 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1036,6 +1036,8 @@ dependencies = [
  "log",
  "thiserror 2.0.12",
  "tokio",
+ "tokio-condvar",
+ "uuid",
 ]
 
 [[package]]
@@ -1386,35 +1388,14 @@ version = "5.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "74765f6d916ee2faa39bc8e68e4f3ed8949b48cccdac59983d287a7cb71ce9c5"
 
-[[package]]
-name = "rand"
-version = "0.8.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
-dependencies = [
- "libc",
- "rand_chacha 0.3.1",
- "rand_core 0.6.4",
-]
-
 [[package]]
 name = "rand"
 version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9fbfd9d094a40bf3ae768db9361049ace4c0e04a4fd6b359518bd7b73a73dd97"
 dependencies = [
- "rand_chacha 0.9.0",
- "rand_core 0.9.3",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
-dependencies = [
- "ppv-lite86",
- "rand_core 0.6.4",
+ "rand_chacha",
+ "rand_core",
 ]
 
 [[package]]
@@ -1424,16 +1405,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
 dependencies = [
  "ppv-lite86",
- "rand_core 0.9.3",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.6.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
-dependencies = [
- "getrandom 0.2.14",
+ "rand_core",
 ]
 
 [[package]]
@@ -1821,6 +1793,15 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "tokio-condvar"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8530e402d24f6a65019baa57593f1769557c670302f493cdf8fa3dfbe4d85ac"
+dependencies = [
+ "tokio",
+]
+
 [[package]]
 name = "tokio-macros"
 version = "2.5.0"
@@ -1944,7 +1925,7 @@ dependencies = [
  "http 1.3.1",
  "httparse",
  "log",
- "rand 0.9.1",
+ "rand",
  "sha1",
  "thiserror 2.0.12",
  "utf-8",
@@ -1988,20 +1969,20 @@ checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
 [[package]]
 name = "uuid"
-version = "1.11.0"
+version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8c5f0a0af699448548ad1a2fbf920fb4bee257eae39953ba95cb84891a0446a"
+checksum = "458f7a779bf54acc9f347480ac654f68407d3aab21269a6e3c9f922acd9e2da9"
 dependencies = [
- "getrandom 0.2.14",
- "rand 0.8.5",
+ "getrandom 0.3.2",
+ "rand",
  "uuid-macro-internal",
 ]
 
 [[package]]
 name = "uuid-macro-internal"
-version = "1.11.0"
+version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b91f57fe13a38d0ce9e28a03463d8d3c2468ed03d75375110ec71d93b449a08"
+checksum = "72dcd78c4f979627a754f5522cea6e6a25e55139056535fe6e69c506cd64a862"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/kordophone/src/api/http_client.rs b/kordophone/src/api/http_client.rs
index 1a9c3c4..63d2522 100644
--- a/kordophone/src/api/http_client.rs
+++ b/kordophone/src/api/http_client.rs
@@ -227,7 +227,7 @@ impl<K: AuthenticationStore + Send + Sync> APIInterface for HTTPAPIClient<K> {
 
     async fn send_message(
         &mut self, 
-        outgoing_message: OutgoingMessage,
+        outgoing_message: &OutgoingMessage,
     ) -> Result<Message, Self::Error> {
         let message: Message = self.request_with_body(
             "sendMessage", 
diff --git a/kordophone/src/api/mod.rs b/kordophone/src/api/mod.rs
index 81f8fae..d711948 100644
--- a/kordophone/src/api/mod.rs
+++ b/kordophone/src/api/mod.rs
@@ -15,10 +15,11 @@ pub mod event_socket;
 pub use event_socket::EventSocket;
 
 use self::http_client::Credentials;
+use std::fmt::Debug;
 
 #[async_trait]
 pub trait APIInterface {
-    type Error;
+    type Error: Debug;
 
     // (GET) /version
     async fn get_version(&mut self) -> Result<String, Self::Error>;
@@ -38,7 +39,7 @@ pub trait APIInterface {
     // (POST) /sendMessage
     async fn send_message(
         &mut self, 
-        outgoing_message: OutgoingMessage,
+        outgoing_message: &OutgoingMessage,
     ) -> Result<Message, Self::Error>;
 
     // (POST) /authenticate
diff --git a/kordophone/src/model/outgoing_message.rs b/kordophone/src/model/outgoing_message.rs
index 1f13d2f..530b741 100644
--- a/kordophone/src/model/outgoing_message.rs
+++ b/kordophone/src/model/outgoing_message.rs
@@ -1,8 +1,12 @@
 use serde::Serialize;
 use super::conversation::ConversationID;
+use uuid::Uuid;
 
 #[derive(Debug, Clone, Serialize)]
 pub struct OutgoingMessage {
+    #[serde(skip)]
+    pub guid: Uuid,
+
     #[serde(rename = "body")]
     pub text: String,
 
@@ -21,6 +25,7 @@ impl OutgoingMessage {
 
 #[derive(Default)]
 pub struct OutgoingMessageBuilder {
+    guid: Option<Uuid>,
     text: Option<String>,
     conversation_id: Option<ConversationID>,
     file_transfer_guids: Option<Vec<String>>,
@@ -31,6 +36,11 @@ impl OutgoingMessageBuilder {
         Self::default()
     }
 
+    pub fn guid(mut self, guid: Uuid) -> Self {
+        self.guid = Some(guid);
+        self
+    }
+
     pub fn text(mut self, text: String) -> Self {
         self.text = Some(text);
         self
@@ -48,6 +58,7 @@ impl OutgoingMessageBuilder {
 
     pub fn build(self) -> OutgoingMessage {
         OutgoingMessage { 
+            guid: self.guid.unwrap_or_else(|| Uuid::new_v4()),
             text: self.text.unwrap(), 
             conversation_id: self.conversation_id.unwrap(), 
             file_transfer_guids: self.file_transfer_guids.unwrap_or_default(),
diff --git a/kordophone/src/tests/test_client.rs b/kordophone/src/tests/test_client.rs
index fdc3eff..4edd627 100644
--- a/kordophone/src/tests/test_client.rs
+++ b/kordophone/src/tests/test_client.rs
@@ -93,15 +93,15 @@ impl APIInterface for TestClient {
 
     async fn send_message(
         &mut self, 
-        outgoing_message: OutgoingMessage,
+        outgoing_message: &OutgoingMessage,
     ) -> Result<Message, Self::Error> {
         let message = Message::builder()
             .guid(Uuid::new_v4().to_string())
-            .text(outgoing_message.text)
+            .text(outgoing_message.text.clone())
             .date(OffsetDateTime::now_utc())
             .build();
 
-        self.messages.entry(outgoing_message.conversation_id).or_insert(vec![]).push(message.clone());
+        self.messages.entry(outgoing_message.conversation_id.clone()).or_insert(vec![]).push(message.clone());
         Ok(message)
     }
 
diff --git a/kordophoned/Cargo.toml b/kordophoned/Cargo.toml
index 74c2556..7891e35 100644
--- a/kordophoned/Cargo.toml
+++ b/kordophoned/Cargo.toml
@@ -18,6 +18,8 @@ kordophone-db = { path = "../kordophone-db" }
 log = "0.4.25"
 thiserror = "2.0.12"
 tokio = { version = "1", features = ["full"] }
+tokio-condvar = "0.3.0"
+uuid = "1.16.0"
 
 [build-dependencies]
 dbus-codegen = "0.10.0"
diff --git a/kordophoned/include/net.buzzert.kordophonecd.Server.xml b/kordophoned/include/net.buzzert.kordophonecd.Server.xml
index b346742..01fb1c3 100644
--- a/kordophoned/include/net.buzzert.kordophonecd.Server.xml
+++ b/kordophoned/include/net.buzzert.kordophonecd.Server.xml
@@ -58,6 +58,15 @@
             <arg type="aa{sv}" direction="out" name="messages"/>
         </method>
 
+        <method name="SendMessage">
+            <arg type="s" name="conversation_id" direction="in"/>
+            <arg type="s" name="text" direction="in"/>
+            <arg type="s" name="outgoing_message_id" direction="out"/>
+
+            <annotation name="org.freedesktop.DBus.DocString" 
+                        value="Sends a message to the server. Returns the outgoing message ID."/>
+        </method>
+
         <signal name="MessagesUpdated">
             <arg type="s" name="conversation_id" direction="in"/>
             <annotation name="org.freedesktop.DBus.DocString" 
diff --git a/kordophoned/src/daemon/events.rs b/kordophoned/src/daemon/events.rs
index b356992..61e50f8 100644
--- a/kordophoned/src/daemon/events.rs
+++ b/kordophoned/src/daemon/events.rs
@@ -1,4 +1,6 @@
 use tokio::sync::oneshot;
+use uuid::Uuid;
+
 use kordophone_db::models::{Conversation, Message};
 use crate::daemon::settings::Settings;
 
@@ -33,6 +35,13 @@ pub enum Event {
     /// - last_message_id: (optional) The ID of the last message to get. If None, all messages are returned.
     GetMessages(String, Option<String>, Reply<Vec<Message>>),
 
+    /// Enqueues a message to be sent to the server.
+    /// Parameters: 
+    /// - conversation_id: The ID of the conversation to send the message to.
+    /// - text: The text of the message to send.
+    /// - reply: The outgoing message ID (not the server-assigned message ID).
+    SendMessage(String, String, Reply<Uuid>),
+
     /// Delete all conversations from the database.
     DeleteAllConversations(Reply<()>),
 }
diff --git a/kordophoned/src/daemon/mod.rs b/kordophoned/src/daemon/mod.rs
index 4af1875..f4eeda0 100644
--- a/kordophoned/src/daemon/mod.rs
+++ b/kordophoned/src/daemon/mod.rs
@@ -16,6 +16,7 @@ use thiserror::Error;
 use tokio::sync::mpsc::{Sender, Receiver};
 use std::sync::Arc;
 use tokio::sync::Mutex;
+use uuid::Uuid;
 
 use kordophone_db::{
     database::{Database, DatabaseAccess},
@@ -24,6 +25,7 @@ use kordophone_db::{
 
 use kordophone::api::APIInterface;
 use kordophone::api::http_client::HTTPAPIClient;
+use kordophone::model::outgoing_message::OutgoingMessage;
 
 mod update_monitor;
 use update_monitor::UpdateMonitor;
@@ -31,6 +33,10 @@ use update_monitor::UpdateMonitor;
 mod auth_store;
 use auth_store::DatabaseAuthenticationStore;
 
+mod post_office;
+use post_office::PostOffice;
+use post_office::Event as PostOfficeEvent;
+
 #[derive(Debug, Error)]
 pub enum DaemonError {
     #[error("Client Not Configured")]
@@ -52,6 +58,9 @@ pub struct Daemon {
     signal_receiver: Option<Receiver<Signal>>,
     signal_sender: Sender<Signal>,
 
+    post_office_sink: Sender<PostOfficeEvent>,
+    post_office_source: Option<Receiver<PostOfficeEvent>>,
+
     version: String,
     database: Arc<Mutex<Database>>,
     runtime: tokio::runtime::Runtime,
@@ -69,6 +78,7 @@ impl Daemon {
         // Create event channels
         let (event_sender, event_receiver) = tokio::sync::mpsc::channel(100);
         let (signal_sender, signal_receiver) = tokio::sync::mpsc::channel(100);
+        let (post_office_sink, post_office_source) = tokio::sync::mpsc::channel(100);
         // Create background task runtime 
         let runtime = tokio::runtime::Builder::new_multi_thread()
             .enable_all()
@@ -84,6 +94,8 @@ impl Daemon {
             event_sender, 
             signal_receiver: Some(signal_receiver),
             signal_sender, 
+            post_office_sink,
+            post_office_source: Some(post_office_source),
             runtime 
         })
     }
@@ -92,12 +104,23 @@ impl Daemon {
         log::info!("Starting daemon version {}", self.version);
         log::debug!("Debug logging enabled.");
 
+        // Update monitor
         let mut update_monitor = UpdateMonitor::new(self.database.clone(), self.event_sender.clone());
-
         tokio::spawn(async move {
             update_monitor.run().await; // should run indefinitely
         });
 
+        // Post office
+        {
+            let mut database = self.database.clone();
+            let event_sender = self.event_sender.clone();
+            let post_office_source = self.post_office_source.take().unwrap();
+            tokio::spawn(async move {
+                let mut post_office = PostOffice::new(post_office_source, event_sender, async move || Self::get_client_impl(&mut database).await );
+                post_office.run().await;
+            });
+        }
+
         while let Some(event) = self.event_receiver.recv().await {
             log::debug!(target: target::EVENT, "Received event: {:?}", event);
             self.handle_event(event).await;
@@ -188,6 +211,11 @@ impl Daemon {
 
                 reply.send(()).unwrap();
             },
+
+            Event::SendMessage(conversation_id, text, reply) => {
+                let uuid = self.enqueue_outgoing_message(text, conversation_id).await;
+                reply.send(uuid).unwrap();
+            },
         }
     }
 
@@ -204,6 +232,18 @@ impl Daemon {
         self.database.lock().await.with_repository(|r| r.get_messages_for_conversation(&conversation_id).unwrap()).await
     }
 
+    async fn enqueue_outgoing_message(&mut self, text: String, conversation_id: String) -> Uuid {
+        let outgoing_message = OutgoingMessage::builder()
+            .text(text)
+            .conversation_id(conversation_id)
+            .build();
+
+        let guid = outgoing_message.guid.clone();
+        self.post_office_sink.send(PostOfficeEvent::EnqueueOutgoingMessage(outgoing_message)).await.unwrap();
+        
+        guid
+    }
+
     async fn sync_conversation_list(database: &mut Arc<Mutex<Database>>, signal_sender: &Sender<Signal>) -> Result<()> {
         log::info!(target: target::SYNC, "Starting list conversation sync");
 
diff --git a/kordophoned/src/daemon/post_office.rs b/kordophoned/src/daemon/post_office.rs
new file mode 100644
index 0000000..88ebe30
--- /dev/null
+++ b/kordophoned/src/daemon/post_office.rs
@@ -0,0 +1,115 @@
+use std::collections::VecDeque;
+use std::time::Duration;
+
+use tokio::sync::mpsc::{Sender, Receiver};
+use tokio::sync::{Mutex, MutexGuard};
+use tokio_condvar::Condvar;
+
+use crate::daemon::events::Event as DaemonEvent;
+use kordophone::model::outgoing_message::OutgoingMessage;
+use kordophone::api::APIInterface;
+
+use anyhow::Result;
+
+mod target {
+    pub static POST_OFFICE: &str = "post_office";
+}
+
+#[derive(Debug)]
+pub enum Event {
+    EnqueueOutgoingMessage(OutgoingMessage),
+}
+
+pub struct PostOffice<C: APIInterface, F: AsyncFnMut() -> Result<C>> {
+    event_source: Receiver<Event>,
+    event_sink: Sender<DaemonEvent>,
+    make_client: F,
+    message_queue: Mutex<VecDeque<OutgoingMessage>>,
+    message_available: Condvar, 
+}
+
+impl<C: APIInterface, F: AsyncFnMut() -> Result<C>> PostOffice<C, F> {
+    pub fn new(event_source: Receiver<Event>, event_sink: Sender<DaemonEvent>, make_client: F) -> Self {
+        Self { 
+            event_source,
+            event_sink, 
+            make_client, 
+            message_queue: Mutex::new(VecDeque::new()),
+            message_available: Condvar::new(),
+        }
+    }
+
+    pub async fn queue_message(&mut self, message: &OutgoingMessage) {
+        self.message_queue.lock().await.push_back(message.clone());
+        self.message_available.notify_one();
+    }
+
+    pub async fn run(&mut self) {
+        log::info!(target: target::POST_OFFICE, "Starting post office");
+
+        loop {
+            let mut retry_messages = Vec::new();
+
+            log::debug!(target: target::POST_OFFICE, "Waiting for event");
+
+            tokio::select! {
+                // Incoming events
+                Some(event) = self.event_source.recv() => {
+                    match event {
+                        Event::EnqueueOutgoingMessage(message) => {
+                            log::debug!(target: target::POST_OFFICE, "Received enqueue outgoing message event");
+                            self.message_queue.lock().await.push_back(message);
+                            self.message_available.notify_one();
+                        }
+                    }
+                }
+
+                // Message queue
+                mut lock = self.message_available.wait(self.message_queue.lock().await) => {
+                    log::debug!(target: target::POST_OFFICE, "Message available in queue");
+                    retry_messages = Self::try_send_message_impl(&mut lock, &mut self.make_client).await;
+                }
+            }
+
+            if !retry_messages.is_empty() {
+                log::debug!(target: target::POST_OFFICE, "Queueing {} messages for retry", retry_messages.len());
+                for message in retry_messages {
+                    self.queue_message(&message).await;
+                }
+            }
+        }
+    }
+
+    async fn try_send_message_impl(message_queue: &mut MutexGuard<'_, VecDeque<OutgoingMessage>>, make_client: &mut F) -> Vec<OutgoingMessage> {
+        log::debug!(target: target::POST_OFFICE, "Trying to send enqueued messages");
+
+        let mut retry_messages = Vec::new();
+        while let Some(message) = message_queue.pop_front() {
+            match (make_client)().await {
+                Ok(mut client) => {
+                    log::debug!(target: target::POST_OFFICE, "Obtained client, sending message.");
+                    match client.send_message(&message).await {
+                        Ok(message) => {
+                            log::info!(target: target::POST_OFFICE, "Message sent successfully: {}", message.guid);
+                            // TODO: Notify the daemon via the event sink. 
+                        }
+                        Err(e) => {
+                            log::error!(target: target::POST_OFFICE, "Error sending message: {:?}", e);
+                            log::warn!(target: target::POST_OFFICE, "Retrying in 5 seconds");
+                            tokio::time::sleep(Duration::from_secs(5)).await;
+                            retry_messages.push(message);
+                        }
+                    }
+                }
+
+                Err(e) => {
+                    log::error!(target: target::POST_OFFICE, "Error creating client: {:?}", e);
+                    log::warn!(target: target::POST_OFFICE, "Retrying in 5 seconds");
+                    tokio::time::sleep(Duration::from_secs(5)).await;
+                }
+            }
+        }
+
+        retry_messages
+    }
+}
\ No newline at end of file
diff --git a/kordophoned/src/dbus/server_impl.rs b/kordophoned/src/dbus/server_impl.rs
index 5c00a58..2dc8a38 100644
--- a/kordophoned/src/dbus/server_impl.rs
+++ b/kordophoned/src/dbus/server_impl.rs
@@ -102,6 +102,11 @@ impl DbusRepository for ServerImpl {
     fn delete_all_conversations(&mut self) -> Result<(), dbus::MethodErr> {
         self.send_event_sync(Event::DeleteAllConversations)
     }
+
+    fn send_message(&mut self, conversation_id: String, text: String) -> Result<String, dbus::MethodErr> {
+        self.send_event_sync(|r| Event::SendMessage(conversation_id, text, r))
+            .map(|uuid| uuid.to_string())
+    }
 } 
 
 impl DbusSettings for ServerImpl {
diff --git a/kpcli/src/client/mod.rs b/kpcli/src/client/mod.rs
index d805f9e..9356d33 100644
--- a/kpcli/src/client/mod.rs
+++ b/kpcli/src/client/mod.rs
@@ -138,7 +138,7 @@ impl ClientCli {
             .text(message)
             .build();
 
-        let message = self.api.send_message(outgoing_message).await?;
+        let message = self.api.send_message(&outgoing_message).await?;
         println!("Message sent: {}", message.guid);
         Ok(())
     }
diff --git a/kpcli/src/daemon/mod.rs b/kpcli/src/daemon/mod.rs
index ad5b52f..26bafd9 100644
--- a/kpcli/src/daemon/mod.rs
+++ b/kpcli/src/daemon/mod.rs
@@ -48,6 +48,12 @@ pub enum Commands {
 
     /// Deletes all conversations.
     DeleteAllConversations,
+
+    /// Enqueues an outgoing message to be sent to a conversation.
+    SendMessage {
+        conversation_id: String,
+        text: String,
+    },
 }
 
 #[derive(Subcommand)]
@@ -83,6 +89,7 @@ impl Commands {
             Commands::Signals => client.wait_for_signals().await,
             Commands::Messages { conversation_id, last_message_id } => client.print_messages(conversation_id, last_message_id).await,
             Commands::DeleteAllConversations => client.delete_all_conversations().await,
+            Commands::SendMessage { conversation_id, text } => client.enqueue_outgoing_message(conversation_id, text).await,
         }
     }
 }
@@ -145,6 +152,12 @@ impl DaemonCli {
         Ok(())
     }
 
+    pub async fn enqueue_outgoing_message(&mut self, conversation_id: String, text: String) -> Result<()> {
+        let outgoing_message_id = KordophoneRepository::send_message(&self.proxy(), &conversation_id, &text)?;
+        println!("Outgoing message ID: {}", outgoing_message_id);
+        Ok(())
+    }
+
     pub async fn wait_for_signals(&mut self) -> Result<()> {
         use dbus::Message;
         mod dbus_signals {