After review of your user ID, I am currently seeing a filter sending your emails directly to a third-party email. This is causing your emails not to be delivered to your inbox but to a third-party email.
You can remove the filter under emails settings. This will allow amazon messages to go back to your inbox directly. If you did not setup this filter, then it is highly likely your account has been compromised. You will want to update your password, any third-party recovery options, and will probably want to setup the two-step verification portion of your user ID.
If you need any assistance with this, please call our Customer Security Assurance Department at 888-565-4329.