NginX reverse proxy with iRedMail Apache2

[sim4life]

I changed the faulty line in NginX default config file to:

server {
        listen 80 default_server;
        listen [::]:80;

        root /usr/share/nginx/html;
        index index.html index.htm index.php;

        server_name mydomain.com www.mydomain.com;

        location / {
                proxy_set_header X-Real-IP  $remote_addr;
                proxy_set_header X-Forwarded-For
$proxy_add_x_forwarded_for;
                proxy_set_header Host $host;
                proxy_pass http://127.0.0.1:8080;
        }

        location ~ /\.ht {
                deny all;
        }
}

So now, on hitting in the browser:
https://mail.mydomain.com

I get the error on the browser:
This webpage has a redirect loop
The webpage at https://mail.mydomain.com/ has resulted in too many
redirects. Clearing your cookies for this site or allowing third-party
cookies may fix the problem. If not, it is possibly a server configuration
issue and not a problem with your computer.

The NginX error is gone but the Apache error remains the same. 
I think it's some config problem with setup of iRedMail so I'm going to
decommission Apache2 for iRedMail setup and move the entire iRedMail setup
on NginX directly.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,249312,249382#msg-249382