When you send a chat message in the Teams desktop app and see a red exclamation mark with the text Delivery failed, the message did not reach the recipient. This usually happens because of a temporary network outage, a problem with the Teams service, or a policy that blocks external messaging. This article explains the root causes and gives you a clear sequence of steps to clear the error and resend your message.
You will also learn how to check the Teams service health, verify your network connection, and adjust chat policies if your organization restricts external contacts. The fixes below work for both Windows 11 and Windows 10 desktop apps. After following them, you will be able to send messages reliably again.
Key Takeaways: Fixing Delivery Failed in Teams Desktop Chat
- Teams admin center > Org-wide settings > Teams service health: Shows live incidents that can cause message delivery failures.
- Ctrl+Shift+Esc > Performance tab > Network: Helps you confirm whether your local connection is stable before troubleshooting Teams.
- Teams > Settings > Privacy > Manage external access: Controls whether you can chat with people outside your organization.
Why Teams Chat Shows a Delivery Failed Message
The Delivery failed message appears when the Teams desktop client cannot confirm that your message reached the Teams service or the recipient’s client. Teams uses a real-time chat pipeline that requires a stable connection to the Microsoft 365 service. If the client loses connectivity for a few seconds, the message is not sent and the app marks it as failed.
There are four common root causes:
- Network instability: Wi-Fi drops, VPN disconnects, or proxy timeouts interrupt the chat connection.
- Teams service outage: An incident on Microsoft’s side prevents message routing.
- External chat policy: Your administrator may block chats with users outside your tenant, causing a delivery failure.
- Stale client cache: Corrupted local data can make the app think a message failed even when the server accepted it.
The error is not permanent. In most cases you can resend the message after restoring connectivity or after the service recovers. The steps below walk you through each fix in order.
Steps to Diagnose and Fix the Delivery Failed Error
Follow these steps in order. Stop when the error clears and your message sends successfully.
- Check Teams service health
Open the Teams admin center at admin.teams.microsoft.com. Go to Org-wide settings > Teams service health. Look for any advisory or incident under Chat. If an incident exists, wait until it is resolved. Your message will not send until the service is healthy. - Test your network connection
Press Ctrl+Shift+Esc to open Task Manager. Go to the Performance tab and select Network. Look at the utilization graph. If it shows 0% or spikes, your connection is unstable. Disconnect from your VPN and reconnect, or switch from Wi-Fi to a wired connection. Then try sending the message again. - Resend the failed message
In the chat where the error appears, hover over the message with the red exclamation mark. Click the retry icon that appears. If that does not work, right-click the message and select Resend. This forces the client to re-attempt delivery. - Verify external chat permissions
If the recipient is outside your organization, check your external access settings. In Teams, click your profile picture, then Settings > Privacy > Manage external access. Confirm that the toggle for Chat with external users is on. If it is off, turn it on. Note that your administrator may still block external chats through policy. - Check your Teams version
Click your profile picture, then select About. Compare the version number with the latest release on the Microsoft 365 roadmap. If your version is older than two months, update Teams by clicking Check for updates in the same menu. Outdated clients often have known chat bugs. - Clear the Teams cache
Close Teams completely. Press Ctrl+Shift+Escape and end the Teams process if it is still running. Open File Explorer and navigate to %appdata%\Microsoft\Teams. Delete the folders named Cache, Code Cache, GPUCache, and tmp. Restart Teams and sign in again. This clears corrupted data that can cause false delivery failures. - Reset the Teams app
If the cache clear does not help, uninstall Teams from Settings > Apps > Installed apps. Reboot your computer. Download the latest Teams installer from the Microsoft website and install it. Sign in with your work or school account. Your chats are stored on the server, so you will not lose any messages.
If Teams Still Shows Delivery Failed After the Main Fix
Teams Shows Delivery Failed for One Specific Contact
If the error only appears when you message one person, that person may have blocked you or left the organization. Ask the person to check their privacy settings. If they left the company, the message will never deliver. You can delete the failed message by right-clicking it and selecting Delete.
Delivery Failed Appears After a Policy Change
Your administrator may have changed a messaging policy that now blocks certain chat types. Contact your IT support and ask them to check the Teams messaging policies assigned to your account. They can see the effective policy in Teams admin center > Users > Manage users > Policies.
Delivery Failed Only on the Desktop App, Not on Mobile
If the message sends from your mobile Teams app but not from the desktop app, the desktop client has a corrupted state. Use the cache clear and reset steps above. If the issue persists, try signing out of Teams and signing back in. This refreshes the local session without removing your chats.
Teams Desktop App vs Teams on the Web: Delivery Behavior Compared
| Item | Teams Desktop App | Teams on the Web |
|---|---|---|
| Delivery error display | Red exclamation mark on the message bubble | Same red exclamation mark |
| Cache clearing | Manual folder deletion in %appdata% | Browser cache clear |
| Update method | Check for updates in the app | Automatic browser update |
| External chat policy | Controlled by admin policy | Same policy applies |
| Network sensitivity | Requires persistent connection | Can recover faster on reload |
If the desktop app keeps failing, try Teams on the web as a temporary workaround. Open a browser, go to teams.microsoft.com, and sign in. Your chat history appears there. You can send the message from the web version while you fix the desktop client.
After you complete the fixes, you can send messages without the Delivery failed error. Start by checking the Teams service health and your network connection. Then use the retry option to resend any stuck messages. If the problem persists, clear the cache or reinstall the app. As an advanced tip, use the Teams diagnostic tool by running the command teams.exe –diag in the Run dialog to generate a detailed log for your IT support team.