Is my TLSFTP connection secure?

What is difference in the below Two commands?

1) tlsftp -v -d -i -a -z verify=0 opts=17 $SERVERNAME << !

2) tlsftp -i -v -n ${ SERVERNAME } << !

Presently I am using the second command for get the files from Mainframe system to Unix system. But it is not secure.

Now i want to modify the code to make the connection secure. If I use the first command, is my connection is secure?

Please let me know.

Thanks in advance