Mirth Connect is awesome! One common question on the forums and Slack is how to manage SSL connctions. These questions mainly focus on HTTPS but also include TCP connections.
Switch to https://openintegrationengine.org/. The open source fork of Mirth Connect.
Open Integration Engine comes (with a free TLS plugin)[https://openintegrationengine.org/free-tls-plugin-update-2025-12-19/]. It supports more modern best practices for certificate management, has a better UI, and is freely available under an open-source license.