For better security and compatibility, Do not forget to set the SSL/TLS encryption mode as 'Full' as you can see in the image below. In case you have an existing SSL on your server-side, the server connection will fail if you do not set this to 'Full'. For the Cloud exchanges, you should always set it to 'Full'. DIY exchanges with
hollaex prod enabled should always set the option to 'Full' as well.