What to Do When Your Allo Message Is Not Delivered
Understand Allo message delivery statuses and take the right steps when a message stays stuck on sent, pending, or undelivered in the mesh.
Allo is designed for reliable off-grid communication, not instant internet chat. Messages travel over a radio mesh network — they are stored by each device that receives them and forwarded hop-by-hop until they reach the recipient. This means delivery can take a few seconds longer than you might expect on a mobile network, and delivery confirmation works differently than it does with SMS or internet messaging apps.
How message delivery works
Every message you send moves through several stages before it reaches its destination. Understanding these stages helps you interpret what the app is telling you and decide what action to take.
Composed on your phone
You type your message and tap Send. The message is held in the app, waiting for your phone to hand it off to your paired Allo client device over Bluetooth.
Received by your Allo device
Your phone transfers the message to your Allo device over the Bluetooth link. Once the device has accepted the message, the app updates the status to confirm it has left the phone. If your phone is not connected to the device, the message will wait in the app until the Bluetooth link is restored.
Transmitted over the radio mesh
Your device broadcasts the message over the LoRa radio network. The message travels across the mesh — relayed by other devices and repeaters — until it reaches a device within range of the recipient. The more repeaters there are between sender and recipient, the longer this can take. On a healthy network, delivery usually takes a few seconds; on a sparse mesh or over long distances, it may take longer.
Delivered to the recipient's device
The recipient's Allo device receives the message and sends an acknowledgement back across the mesh to your device. Your device forwards that acknowledgement to your phone over Bluetooth, and the app marks the message as delivered. The recipient will see the message the next time their phone syncs with their device.
Because acknowledgements also travel over the radio mesh, delivery confirmation can arrive a few seconds after the message itself. A brief delay between sending and seeing the delivered status is normal — it does not mean the message was lost.
What the delivery status icons mean
| Status | What it means |
|---|---|
| Sending | The message is queued in the app, waiting to be passed to the Allo device over Bluetooth. |
| Sent | The message has been handed off from the app to your paired Allo device. |
| Delivered | The recipient's device has received the message and sent back an acknowledgement. |
| Failed / Undelivered | The device could not confirm delivery after repeated attempts. See the checks below. |
What to do when a message stays undelivered
Check your own Bluetooth connection
Look at the connection indicator in the app. If your phone is not connected to your Allo device, the message cannot leave the phone at all. If you see a connection warning, follow the steps in the Bluetooth connection problems guide, then resend the message.
Check that the antenna is properly fitted
A loose or missing antenna dramatically reduces the range of the radio transmission. Make sure the antenna on your Allo device is screwed on firmly by hand. Do not use tools. If the antenna is missing or the connector is damaged, do not use the device and report it to your administrator.
Check that you are within range of the radio mesh
If you are indoors — especially in a building with thick concrete walls, steel reinforcement, or underground — the radio signal may not reach the mesh at all. Move to a window, step outside, or move to a higher floor and retry. For guidance on range and obstacles, see Poor range.
Confirm the recipient is reachable
The recipient's device must also be within the mesh for the message to be delivered. If they are out of range of any repeater or other device, delivery is not possible until they move back into coverage. Ask the recipient to confirm they are connected and within range.
Wait and retry
Allo automatically retries undelivered messages. If the network is temporarily congested or a hop is temporarily unavailable, the device will keep trying. Wait 60 seconds and check whether the status has updated before resending manually. Resending the same message multiple times can cause duplicates when the network recovers.
Resend if still undelivered after several minutes
If the message shows no delivery progress after several minutes and you have confirmed both devices are connected and within range, open the message and use the Resend option. If the problem persists across multiple messages to the same recipient, the issue is likely range or coverage — see Poor range.
Allo is a supplement to, not a replacement for, established emergency communication procedures. If you cannot confirm delivery of a critical message, use your organisation's backup communication methods. Do not rely solely on a single unconfirmed Allo message in a life-safety situation.
Delayed messages
Allo is designed for robust emergency communication, not internet-speed chat. Messages can sometimes take several seconds — or longer — to arrive, particularly when they travel through multiple repeater hops or when the network is under heavy load. A message being slow to arrive is not the same as it being undelivered.
Delays are more likely when:
- The sender and recipient are far apart and there are several hops between them.
- The signal is weak due to obstacles or distance from a repeater.
- The mesh is busy with traffic from many users simultaneously.
- The message is being retried after a failed first attempt.
If messages are consistently slow rather than failing outright, the likely cause is coverage — read the Poor range guide for advice on improving it.
When to escalate
Contact your organisation administrator if:
- Multiple users report that messages between specific locations consistently fail to deliver.
- A device in a fixed position (such as a repeater or a base device) stops acknowledging messages.
- Delivery works between some users but not others, suggesting a coverage gap in the mesh.
Your administrator can review delivery logs in the dashboard and, if necessary, arrange for an additional repeater to be placed to fill a coverage gap.