在jwilder-nginx-proxy后部署iRedMail遇301重定向过多问题求助

首次部署iRedMail，尝试在已运行多Web应用、由jwilder/docker-gen管理Let's Encrypt证书的反向代理环境下部署iredmail/mariadb:stable，但访问mail.domain.com时出现ERR_TOO_MANY_REDIRECTS（301 Moved Permanently）错误，耗时排查仍未解决，求修复思路。

iredmail-docker.conf配置文件 #

HOSTNAME=webmail.domain.com
FIRST_MAIL_DOMAIN=domain.com
FIRST_MAIL_DOMAIN_ADMIN_PASSWORD=myp@ssw0rd
MLMMJADMIN_API_TOKEN=$(openssl rand -base64 32)
ROUNDCUBE_DES_KEY=$(openssl rand -base64 24)

docker-compose.yml配置文件 #

version: '3.9'
services:
  iredmail:
    container_name: iredmail
    image: iredmail/mariadb:stable
    hostname: webmail.domain.com
    environment:
      # NGINX-PROXY ENVIRONMENT VARIABLES: UPDATE ME
      - VIRTUAL_HOST=webmail.domain.com
      - VIRTUAL_PORT=80
      - LETSENCRYPT_HOST=webmail.domain.com
      - LETSENCRYPT_EMAIL=admin@domain.com
      # END NGINX-PROXY ENVIRONMENT VARIABLES
      
    ports:
      # change the host ports to any available ports on your system, for example 8080 and 8443
      - "10080:80"
      - "10443:443"
      # keep the other ports unchanged
      - "110:110"
      - "995:995"
      - "143:143"
      - "993:993"
      - "25:25"
      - "465:465"
      - "587:587"
    volumes:
      - ./data/backup-mysql:/var/vmail/backup/mysql
      - ./data/mailboxes:/var/vmail/vmail1
      - ./data/mlmmj:/var/vmail/mlmmj
      - ./data/mlmmj-archive:/var/vmail/mlmmj-archive
      - ./data/imapsieve_copy:/var/vmail/imapsieve_copy
      - ./data/custom:/opt/iredmail/custom
      - ./data/ssl:/opt/iredmail/ssl
      - ./data/mysql:/var/lib/mysql
      - ./data/clamav:/var/lib/clamav
      - ./data/sa_rules:/var/lib/spamassassin
      - ./data/postfix_queue:/var/spool/postfix

    env_file:
      - iredmail-docker.conf
    networks:
    ....

内容的提问来源于stack exchange，提问作者BoCyrill