I have not found an entry to set up the TLS Protocol, how can I fix this?

Hi,
I am trying to configure smtp settings as below.

SMTP Host: smtp.office365.com

SMTP Port: 587

SSL Protocol: OFF

TLS Protocol: ON

SMTP Username: (your Office365 username)

SMTP Password: (your Office365 password)

On Webmin / Webmin Configuration / Sending Email Page,

I chose [Via SMTP to remote mail server] and I can not find an entry to set the TLS Protocol. Is there a way to solve this problem?

CentOS 6.10 / Webmin 1.900 / Virtualmin 6.04 / Perl 5.010001 / PHP 5.3 /

Thank you.