Hello! I understand you're facing an issue with sending messages and receiving a "Text send failure" notification. Let's work together to figure this out!

1. Check Your Internet Connection: First, make sure your device is connected to the internet and that the connection is stable. You can try opening a webpage to confirm.

2. Recipient's Number: Ensure that you're sending the message to the correct number. Double-check that there are no typos in the phone number.

3. Use a Local Number: Remember, if you're using a toll-free number, it won't work for sending texts via AT&T Office@Hand. Make sure you're using a local number associated with your account 2.

4. Application Status: Sometimes, the issue might stem from server-related problems or app glitches. It might help to restart the AT&T Office@Hand application or even your device.

5. Reinstallation: If the problem persists, you can try uninstalling and then reinstalling the AT&T Office@Hand app.

6. Advanced Troubleshooting: If none of these solutions help, there could be a more significant issue, possibly related to TCR SMS rejections or account settings. I recommend checking out this article for further troubleshooting steps on application rejections 4.

Could you please try these steps and let me know if any of them help resolve the issue? Are you satisfied with the solution I provided, or do you need further assistance?