Mailu/core/nginx/conf/proxy.conf

# Default proxy setup
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header True-Client-IP $remote_addr;
proxy_set_header Forwarded "";
proxy_set_header X-Forwarded-Proto $proxy_x_forwarded_proto;
{% if REAL_IP_HEADER and REAL_IP_FROM %}
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
{% else %}
proxy_set_header X-Forwarded-For $remote_addr;
{% endif %}
proxy_http_version 1.1;