the_prg_server_configuration_old/nix-system-configs/modules/system/mail-server.nix

{
  config,
  pkgs,
  lib,
  ...
}: let
  choose = paths: lib.findFirst builtins.pathExists null paths;
in {
  options.local = {
    hostname = lib.mkOption {
      type = lib.types.str;
      default = "nixos-default";
      description = "System hostname";
    };
    username = lib.mkOption {
      type = lib.types.str;
      default = "user";
      description = "Primary user username";
    };
    userDescription = lib.mkOption {
      type = lib.types.str;
      default = "NixOS User";
      description = "Primary user description";
    };
    address = lib.mkOption {
      type = lib.types.str;
      default = "10.1.1.100";
      description = "Static IP address";
    };
  };

  imports = lib.filter (x: x != null) [
    (choose [./modules/desktop-manager/sway_greetd_homemanager.nix ../desktop-manager/sway_greetd_homemanager.nix])
    (choose [./modules/local/hostname_username.nix ../local/hostname_username.nix])
    (choose [./modules/local/networking_local.nix ../local/networking_local.nix])
    (choose [./modules/bootloader/seabios-assigned-proxmox-at-birth.nix ../bootloader/seabios-assigned-proxmox-at-birth.nix])
    (choose [./modules/lix-default.nix ../lix-default.nix])
    (choose [./modules/secrets-config/sops-the-blank-system.nix ../secrets-config/sops-the-blank-system.nix])
    (choose [./modules/toolsets/grafana_metric.nix ../toolsets/grafana_metric.nix])
    (choose [./modules/secrets-config/sops-mail.nix ../secrets-config/sops-mail.nix])
  ];

  config = {
    # Enable Tailscale for remote access to Traefik dashboard and configuration
    services.tailscale.enable = true;

    local.hostname = "nixos-mailserver";
    local.username = "mailprg";
    local.userDescription = "NixOS PRG Mailing Service";
    local.address = "10.1.1.15";
    system.stateVersion = "25.11";

    services.stalwart-mail = {
      enable = true;
      openFirewall = true;
      settings = {
        server = {
          hostname = "mail.prg-radio.org";
          tls = {
            enable = true;
            implicit = true;
          };
          listener = {
            smtp = {
              protocol = "smtp";
              bind = "[::]:25";
              proxy.trusted-networks = [
                "10.1.1.250/32"
              ];
            };
            submissions = {
              bind = "[::]:465";
              protocol = "smtp";
              tls.implicit = true;
              # Also trust proxy for SMTPS
              proxy.trusted-networks = ["10.1.1.250/32"];
            };
            imaps = {
              bind = "[::]:993";
              protocol = "imap";
              tls.implicit = true;
              proxy.trusted-networks = ["10.1.1.250/32"];
            };
            jmap = {
              bind = "[::]:8080";
              url = "https://mail.prg-radio.org";
              protocol = "http";
            };
            management = {
              bind = ["127.0.0.1:8080"];
              protocol = "http";
            };
          };
        };
        lookup.default = {
          hostname = "mail.prg-radio.org";
          domain = "prg-radio.org";
        };
        acme."letsencrypt" = {
          directory = "https://acme-v02.api.letsencrypt.org/directory";
          challenge = "dns-01";
          contact = config.sops.secrets."cloudflare-username";
          domains = ["prg-radio.org" "mail.prg-radio.org"];
          provider = "cloudflare";
          secret = config.sops.secrets."cloudflare-dns-token";
        };
        session.auth = {
          mechanisms = "[plain]";
          directory = "'in-memory'";
        };
        storage.directory = "in-memory";
        session.rcpt.directory = "'in-memory'";
        directory."imap".lookup.domains = ["prg-radio.org"];
        directory."in-memory" = {
          type = "memory";
          principals = [
            {
              class = "individual";
              name = "Polyteknisk Radiogruppe Board Member";
              secret = config.sops.secrets."board-member-password";
              email = ["board@prg-radio.org"];
            }
            {
              class = "individual";
              name = "postmaster";
              secret = config.sops.secrets."board-member-password";
              email = ["postmaster@prg-radio.org"];
            }
          ];
        };
        authentication.fallback-admin = {
          user = "admin";
          secret = config.sops.secrets."admin-password";
        };
      };
    };
  };
}