OTHER VERSION Postfix for sending email on port 465 using SSL

Hello;

I need to use postfix to send email from openSUSE Leap 42.3, I configured it using Yast --> Network Services --> Mail Server, then in the outgoing mail, I selected use TLS and I did the configuration under Authentication option (so I placed the domain of the outgoing server, the username and the password of the email that I am going to use it).

My questions are:
My email server provider is requesting from me to use SSL and to use port 465, so do I have to do anything other than selecting TLS while configuring the outgoing mail server using yast?
And the to use port 456, where I have to place it?

And how I can do test to send email and confirm that postfix is able to send email using my configured email to other emails?

Regards
Bilal