Teams cannot send messages

Question

I am currently unable to send messages in Microsoft Teams. Whenever I try to send a message in any chat or channel, it fails to deliver and shows a “Failed to send” error.

I have checked my internet connection and restarted the application, but the issue still persists. This problem is affecting my ability to communicate with my team.

Please assist in resolving this issue as soon as possible.

Answer 1

Below is a focused checklist based on Microsoft guidance to help resolve the “Failed to send” error in Microsoft Teams.

• Sign out completely and sign back in Sometimes Teams stays connected in a broken session. On the Teams desktop app (Windows or macOS), select your profile picture in the top right, choose Sign out, fully close Teams, then reopen Teams and sign in again.
• Clear the Microsoft Teams cache If message sending fails across all chats and channels, cache corruption is a likely cause. On Windows, right‑click the Teams icon in the system tray and select Quit. Open File Explorer and go to %appdata%\Microsoft\Teams, delete all contents of that folder, then start Teams and sign in again. On macOS, quit Teams, delete ~/Library/Application Support/Microsoft/Teams, then restart Teams and sign in.

Clearing the cache does not remove Teams or your data.

• Check if a policy is blocking your messages If messages fail immediately after posting, an organizational policy may be blocking them. This can happen due to data protection or communication compliance policies. In these cases, Teams usually shows a message such as “This message was blocked by organizational policy” with a “What can I do?” option. If this appears, the issue must be reviewed by IT and cannot be fixed by restarting Teams.

Try the Teams web version Open Teams in a browser and try sending a message there. If it works in the browser, the issue is likely limited to the desktop app. If it fails in the browser as well, the issue is likely account- or service-related.

Turn off VPN (if in use) If you are connected to a VPN, disconnect from it, restart Teams, and try sending a message again. VPNs can interfere with message delivery.

Check for a Microsoft Teams service incident If all the above steps fail, there may be a temporary service-side issue affecting Teams message delivery.

• If the issue still persists At this point, the issue is likely account-related, tenant policy–related, or service-side. The next step is to contact IT or Microsoft 365 support and clearly state that messages fail in all chats and channels and that the issue persists after sign-out, cache clearing, and browser testing.