Cepee hasn't responded, but I'd guess she's using this service, https://www.anytimemailbox.com/, because they specifically list Austin as an option for mailbox addresses. However, this article gives it a poor review:
https://www.topconsumerreviews.com/best-virtual-mailbox-services/detailed-reviews.php
Global Mail gets great reviews, but the pricing is a bit high. There is a per-page charge for content scans, for example. Based on the reviews, I'm going to give Physical Address a try. They have addresses in Dallas. That'll do for me. I've sent them some questions based on their website. I'll update with the information I find.