我们可以使用 nginx 代理来隐藏来自外部 smtp （如 gmail）的原始服务器暴露吗？

Question

因此，如果可能的话，我想在发送 SMTP 电子邮件（例如从 Gmail 发送）时隐藏我的原始服务器 IP 的暴露，因为我已经多次遭到 DDoS 攻击，仅仅是因为他们从电子邮件中获取 IP。

我也有 Cloudflare，但它仍然泄露了原始 IP。

那么，是否可以采取类似 proxypass 之类的措施来隐藏原始 IP 的暴露？如果可以，请帮助我。

这是我当前的设置，使用 nginx + centos 6。

server {
    listen       80;
    server_name  example.com www.example.com;
    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

    #charset koi8-r;
    #access_log  /var/log/nginx/host.access.log  main;

    location / {
        root /var/www/example.com/html;
        index  index.php;
    }

    #error_page  404              /404.html;

    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /var/www/example.com/html;
    }

    # proxy the PHP scripts to Apache listening on 127.0.0.1:80
    #
    #location ~ \.php$ {
    #    proxy_pass   http://127.0.0.1;
    #}

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    location ~ \.php$ {
        include /etc/nginx/fastcgi_params;
        fastcgi_pass  127.0.0.1:9000;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME /var/www/example.com/html$fastcgi_script_name;
    }