How to configure

I used script to configure a discourse forum on my server, and created app.yml file, then use domain to enter forum, create manager account. But email cannot be sent because SMTP is not working properly. i checked SMTP and the configuration is correct. But still can’t send verification email. Plz help.
github script

My Email is

I do not know how does work.
I use Mailgun: it works correctly with all my 6 Discourse-based forums.

thanks ,that helps a lot