How to install/enable phpmailer

Hello,
I need help regarding installation or enabling of phpmailer for my some of the domains and I have searched here to do it but I can’t find the way to do it.
Please help me and tell me the right way through which I can do it.

Regards,

SSL → MAILSERVER SSL

IN PHPMAILER →

TURN of SMTP

WEBSITES → LIST WEBSITES → MANAGE → SMTP HOST → Add SMTP HOST