With federal inmate texting, messages are relayed using the federal Corrlinks/TRULINCS gadget

https://inmateservice056.hexaforgey.com/posts/federal-inmate-text-app-vs-corrlinks-text-app-key-differences-explained

With federal inmate texting, messages are relayed via the federal Corrlinks/TRULINCS procedure, and replies can go back to the outdoor user as well-known textual content messages.