{ config, lib, ... }:
{
  options.selfprivacy.modules.simple-nixos-mailserver = {
    enable =
      (lib.mkOption {
        default = false;
        type = lib.types.bool;
        description = "Enable mail server";
      })
      // {
        meta = {
          type = "enable";
        };
      };
    location =
      (lib.mkOption {
        type = lib.types.str;
        description = "Location";
      })
      // {
        meta = {
          type = "location";
        };
      };
    enableSso =
      (lib.mkOption {
        default = true;
        type = lib.types.bool;
        description = "Enable SSO for mail server";
      })
      // {
        meta = {
          type = "enable";
        };
      };
  };

  options.sp.email = with lib; mkOption {
    type = types.attrsOf (
      types.submodule (
        { name, ... }: {
          options = {
            subdomain = mkOption {
              type = with types; strMatching "[A-Za-z0-9][A-Za-z0-9\-]{0,61}[A-Za-z0-9]";
              example = "myservice";
              default = config.sp.domain;
              description = "Email subdomain";
            };

            systemdTargets = mkOption {
              type = with types; listOf strMatchig "[a-zA-Z0-9@%:_.\-]+[.](service|socket|device|mount|automount|swap|target|path|timer|scope|slice)";
              default = [];
              example = [ "generate-mastodon-email-password.service" ];
              description = "Systemd target which generates password file.";
            };

            sendOnly = mkOption {
              type = with types; bool;
              default = true;
              example = "false";
              description = "Specifies if the account should be a send-only account. Emails sent to send-only accounts will be rejected.";
            };

            hashedPasswordFile = mkOption {
              type = with types; str;
              example = "/run/keys/mastodon/email_password";
              description = "Path where a file containing password hash located.";
            };
          };
        }
      )
    );

    description = ''
      Don't use this option to create regular users!!!

      This option gives modules possibility to create mailboxes to send emails, e.g. notifications or reminders.
    '';

    example = {
      "noreply@mastodon.example.tld" = {
        hashedPasswordFile = "/run/keys/mastodon/email_password";
        systemdTargets = [ "generate-mastodon-email-password.service" ];
      };
    };
  };
}