SMTP Forward Nginx Proxy

[itpp2012]

Maxim Dounin Wrote:
-------------------------------------------------------
> For your particular task, it may be easier to configure raw TCP 
> proxy to a particular 3rd party SMTP server (e.g., using nginx 
> stream proxy,
> http://nginx.org/en/docs/stream/ngx_stream_core_module.html)
> or a full-featured STMP server with a smarthost configured.

Simple example 2 interfaces balanced backend limited to a vlan routed
gateway:

stream {
  error_log  logs/stream_error_smtp.log;

  upstream backendsmtp {
    server 192.168.28.21:25;
    server 192.168.28.22:25;
    server 192.168.28.23:25;
  }

  server {
    listen 25;
    proxy_connect_timeout 30s;
    proxy_timeout 30s;
    proxy_pass backendsmtp;
    allow 192.168.29.1;
    deny  all;
  }

}

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,263084,263099#msg-263099