I had the same "currently unavailable" problem. Called USAA technical service, and they were absolutely clueless. Said they had never had such a problem. Tried the chat function here, got a Page Currently Unavailable message. Looks like USAA has forgotten what it means to serve.

ticked401,

Thank you for reaching out in Community. If you are still experiencing the problem with Deposit@Mobile, please contact technical support at 877-632-3002. They should be able to provide assistance and if necessary open a trouble ticket for the issue.