Hi there! I understand you're having trouble sending messages using the Dust app on your iPhone running iOS 16.2. Let's work together to get this sorted out.

To start off, could you tell me a bit more about the issue? For example:
- Are you able to open and navigate the app normally?
- Do messages fail to send immediately, or do they seem to hang or show an error?
- Is your internet connection (Wi-Fi or cellular) stable when you try to send messages?
- Have you tried restarting the app or your phone already?

Knowing this will help me offer the best next steps.

Meanwhile, here are some initial simple checks that often help with messaging issues on apps like Dust:

1. Check Network Connection
Make sure your iPhone has a strong internet connection via Wi-Fi or cellular data.

2. Restart the App
Close the Dust app completely (swipe it away from the app switcher) and then reopen it.

3. Restart Your iPhone
Sometimes a quick restart can resolve temporary glitches.

4. Update the Dust App
Open the App Store, go to your account, and check if there's an update available for Dust. Running the latest version can resolve many bugs.

5. Check App Permissions
Go to Settings > Dust and ensure that the app has the necessary permissions enabled, such as network access and notifications.

After you've tried these, if the issue persists, please let me know if any error messages appear or if the app behaves unusually. Additionally, there could be server-side issues or account-related limits, in which case contacting Dust's support at [email protected] might be necessary.

Does this help so far? If you want, I can also guide you through some deeper troubleshooting steps.