Hey Pham,
I suppose you are asking this, what minimum TLS version is supported by apps using Mendix cloud? Answer is - TLS is 1.2+.
For Mendix private cloud, you need to check by the Kubernetes/cloud foundry providers which TLS version they can support.
Hope this helps.
Regards,
Naman Khard
I have checked the Email Connector, it uses version 1.2
Thank you!