{
  config,
  lib,
  pkgs,
  ...
}: let
  exDomain = (import ./ex-domain.nix) lib;
in {
  imports = [
    (builtins.fetchTarball {
      # Pick a commit from the branch you are interested in
      url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/0c1801b48995ec6909e040abedaa56a64f0db430/nixos-mailserver-0c1801b48995ec6909e040abedaa56a64f0db430.tar.gz";
      # And set its hash
      sha256 = "";
    })
  ];

  mailserver = {
    enable = true;
    fqdn = "mail.b12f.io";
    domains = ["b12f.io" exDomain];

    # A list of all login accounts. To create the password hashes, use
    # nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'
    loginAccounts."mail@b12f.io" = {
      hashedPassword = "$2b$05$Ak1YLaRtdBI6h0uwSIzpKuF3v9JIxRBwODrARTLSlPM8guYI1rNmC";
      aliases = ["@example.com"];
    };

    loginAccounts."mail@${exDomain}" = {
      hashedPassword = "$2b$05$wWs55JDK1.LiPqKPF3egfu/3ocEQGihD7hkvLqvVsAzmKSzL0DGdi";
      aliases = [("@" + exDomain)];
    };

    # Use Let's Encrypt certificates. Note that this needs to set up a stripped
    # down nginx and opens port 80.
    certificateScheme = "acme";
  };
}