With federal inmate texting, messages are relayed via the federal Corrlinks/TRULINCS equipment

https://prisonmessaging343.swiftnestly.com/posts/federal-inmate-text-app-vs-corrlinks-text-app-key-differences-explained

With federal inmate texting, messages are relayed as a result of the federal Corrlinks/TRULINCS process, and replies can go back to the external user as original textual content messages.