방화벽 뒤에 discourse 설치하는 방법

I already installed discourse in a server behind a firewall. And an HTTP proxy server was set up by

export https_proxy=http://192.168.1.2:3128
export http_proxy=http://192.168.1.2:3128

But I found that the email sending function is not ok. It’s always timeout, so, I guess it caused by the network setting.

Thanks for your time to read my issues. Any hints are very appreciated.

Your SMTP server is also behind the same firewall?

My SMTP server is the public service from the Internet. Do I need a sock proxy server?