nginx配置mail代理

nginx配置mail代理如下所示：

mail {
  auth_http 127.0.0.1:9091;
  auth_http_header Auth-Channel "fr";
  auth_http_header Auth-SMTP-Host "172.xx.xx.55";
  auth_http_header Auth-SMTP-Port "26";
  ssl_certificate /etc/nginx/ssl/full_chain_rsa.crt;
  ssl_certificate_key /etc/nginx/ssl/private_wildca.key;
  ssl_protocols TLSv1 TLSv1.1 TLSv1.2;  ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE:ECDH:AES:HIGH:!NULL:!aNULL:!MD5:!ADH:!RC4:!DH:!DHE;
  ssl_session_cache shared:SSL:10m;  ssl_session_timeout 10m;
  pop3_capabilities "TOP" "USER";
  imap_capabilities "IMAP4rev1" "UIDPLUS";

  server {
    listen 110;
    protocol pop3;
    proxy on;
  }
  server {
    listen 143;
    protocol imap;
    proxy on;
  }
  server {
    listen 25;
    protocol smtp;
    proxy on;
    smtp_auth login plain;
    xclient on;
  }
  server {
    listen 995 ssl;
    protocol pop3;
    proxy on;
  }
  server {
    listen 993 ssl;
    protocol imap;
    proxy on;
  }
  server {
    listen 465 ssl;
    protocol smtp;
    proxy on;
    smtp_auth login plain;
    xclient on;
  }
}