Caddy反向代理搭建Mailu邮局踩坑记录

网络要求

首先安装docker，并确保服务器的25端口开放，可使用telnet检查

1	telnet smtp.163.com 25

若出现以下信息，证明25端口可用

Trying 111.124.203.45...
Connected to smtp163.mail.ntes53.netease.com.
Escape character is '^]'.
220 163.com Anti-spam GT for Coremail System (163com[20141201])

添加DNS记录

添加A/AAAA记录，解析mail.example.com

安装docker

详细教程请参考Docker CE 软件仓库

生成Mailu配置文件

前往Mailu Setup，根据需求更改

注意：

因为我们要用到Caddy的反代，所以不需要Mailu自动获取Let's Encrypt的证书，需要手动配置，因此Choose how you wish to handle security只能选择mail
Enable Web email client选择一个顺眼的，默认不使用，其他功能按需启用
在Setp 3内，IPv4 listen address请填入本机真实IP，可以是内网IP（一般服务器都有）

修改配置文件

修改Mailu配置

配置完成后点击Setup Mailu，将docker-compose.yml和mailu.env下载到本地进行修改

对于docker-compose.yml

# This file is auto-generated by the Mailu configuration wizard.
# Please read the documentation before attempting any change.
# Generated for compose flavor

services:

  # External dependencies
  redis:
    image: redis:alpine
    restart: always
    volumes:
      - "/mailu/redis:/data"
    depends_on:
      - resolver
    dns:
      - 192.168.203.254

  # Core services
  front:
    image: ghcr.nju.edu.cn/mailu/${DOCKER_PREFIX:-}nginx:${MAILU_VERSION:-2024.06}
    restart: always
    env_file: mailu.env
    logging:
      driver: journald
      options:
        tag: mailu-front
    ports:
    
     #只要不占用Caddy的80/443端口即可！  
      - "172..10.0.1:8080:80"
      - "172..10.0.1:4433:443"
      - "172..10.0.1:25:25"
      - "172..10.0.1:465:465"
      - "172..10.0.1:587:587"
      - "172..10.0.1:110:110"
      - "172..10.0.1:995:995"
      - "172..10.0.1:143:143"
      - "172..10.0.1:993:993"
      - "172..10.0.1:4190:4190"
    networks:
      - default
      - webmail
      - radicale
    volumes:
      - "/mailu/certs:/certs"
      - "/mailu/overrides/nginx:/overrides:ro"
    depends_on:
      - resolver
    dns:
      - 192.168.203.254
......

networks:
  default:
    driver: bridge
    ipam:
      driver: default
      config:
        - subnet: 192.168.203.0/24
  radicale:
    driver: bridge
  webmail:
    driver: bridge
  oletools:
    driver: bridge
    internal: true

只需要在front:里修改80和443的端口即可

对于mailu.env，修改以下内容，防止Caddy反代出现502错误 **！很重要！**折腾了一晚上才搞明白

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REAL_IP_HEADER=X-Real-IP
REAL_IP_FROM=172.10.0.1#你的IP地址
TLS_FLAVOR=mail

Caddy反代配置

mail.example.com {
        encode gzip zstd
        tls {
                protocols tls1.3
        }

        header {
                Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" # HSTS
                Referrer-Policy strict-origin-when-cross-origin
                X-Permitted-Cross-Domain-Policies "none"
                X-Frame-Options SAMEORIGIN
                X-Content-Type-Options nosniff
                X-XSS-Protection "1; mode=block"
                -Server
        }

        reverse_proxy 172.16.0.3:8080 #请自行修改
}