Enforcing SSL connections between a database server and client applications helps protect against man-in-the-middle attacks. SSL connectivity provides a new layer of security by connecting a database server to client applications. This is achieved by encrypting the data stream between the server and the application.
We recommend you set 'Enforce SSL connection' to 'ENABLED' for MySQL Database Server.
resource "azurerm_mysql_server" "recommended" {
...
ssl_enforcement_enabled = true
}