==  What are SSL / TLS / STARTTLS

* These are different ways to encrypt messages for internet communications. 
* SSL is the old name of TLS. They are same.
* But STARTTLS and SSL/TLS are different.
* No-SSL is also called "Non-Secured", "Insecured", "None" or "Plain"

* For advanced users
  * Our server use the latest TLS version 1.3.
  * Some older devices (such as Iphone 6 and Windows 7), are using older version of TLS or SSL. 
  * This is why some devices can't communicate with our sever in a secure way. Use the un-secured communication in these situations.