While SSL connections are commonly thought of as being made to a host, SSL negotiations actually occur at the listener level, before a host is defined. As such, the SSL certificate is applied to the listener.
To select an SSL certificate:
Note: Since SSL can be configured only on FTP listeners, make sure that you select a listener that displays FTP in the Server type column.
If the SSL certificate you want to use is not listed, you can import a certificate from another program. For more information, see Importing an SSL Certificate.
If you do not have an SSL certificate yet, WS_FTP Server can create one. For more information, see Creating an SSL Certificate.