diff --git a/src/components/messages/MessageViewer.vue b/src/components/messages/MessageViewer.vue
index ae1f5eb..f96ef2c 100644
--- a/src/components/messages/MessageViewer.vue
+++ b/src/components/messages/MessageViewer.vue
@@ -33,7 +33,7 @@
 
                                 <!-- state label -->
                                 <div class="my-auto">
-                                    <span v-if="isMessageFailed(message)">Failed</span>
+                                    <span v-if="isMessageFailed(message)">Failed: {{ message.error }}</span>
                                     <span v-else-if="isMessageDelivered(message)">Delivered</span>
                                     <span v-else>Sending</span>
                                 </div>
diff --git a/src/js/Connection.js b/src/js/Connection.js
index 498b295..6d7e336 100644
--- a/src/js/Connection.js
+++ b/src/js/Connection.js
@@ -175,8 +175,13 @@ class Connection {
         // send message
         const message = await GlobalState.connection.sendTextMessage(publicKey, text);
 
+        // mark message as failed after estimated timeout
+        setTimeout(async () => {
+            await Database.Message.setMessageFailedByAckCode(message.expectedAckCrc, "timeout");
+        }, message.estTimeout);
+
         // save to database
-        return await Database.Message.insert({
+        await Database.Message.insert({
             status: "sending",
             to: publicKey,
             from: GlobalState.selfInfo.publicKey,
diff --git a/src/js/Database.js b/src/js/Database.js
index 857d247..4ab0962 100644
--- a/src/js/Database.js
+++ b/src/js/Database.js
@@ -112,7 +112,7 @@ class Message {
 
         // find one latest message by ack code
         // this will prevent updating older messages that might have the same ack code
-        const latestMessageByPacketId = database.messages.findOne({
+        const message = database.messages.findOne({
             selector: {
                 expected_ack_crc: {
                     $eq: ackCode,
@@ -126,12 +126,48 @@ class Message {
         });
 
         // patch the message state
-        return await latestMessageByPacketId.incrementalPatch({
+        return await message.incrementalPatch({
             status: "delivered",
         });
 
     }
 
+    // mark a message as failed by its ack code
+    static async setMessageFailedByAckCode(ackCode, reason) {
+
+        // find one latest message by ack code
+        // this will prevent updating older messages that might have the same ack code
+        const message = await database.messages.findOne({
+            selector: {
+                expected_ack_crc: {
+                    $eq: ackCode,
+                },
+            },
+            sort: [
+                {
+                    timestamp: "desc",
+                },
+            ],
+        }).exec();
+
+        // do nothing if message not found
+        if(!message){
+            return;
+        }
+
+        // do nothing if already delivered
+        if(message.status === "delivered"){
+            return;
+        }
+
+        // patch the message state
+        await message.patch({
+            status: "failed",
+            error: reason,
+        });
+
+    }
+
     // get all messages
     static getAllMessages() {
         return database.messages.find();