Why is my script unable to send mails to users?

My SMTP is not working at all and unable to send mails to users like forgotten password and so on

What do I need to do to make it work perfect because after checking questions n related to my issue on this platform they provide no accurate and solution to website problem someone should help me out.

Kindly check the error i got when testing the forgotten password and my SMTP configuration. Tell me where i need to work on pls