{ pkgs, lib, config, ... }:

{
  services.postfix.enable = true;

  services.postfix.hostname = with lib; with config.networking;
    concatStringsSep "." (filter (x: x != null) [ hostName domain ]);

  services.postfix.relayHost = "smtp.fastmail.com";
  services.postfix.relayPort = 465;

  services.postfix.recipientDelimiter = "+";
  services.postfix.config.home_mailbox = "mail/INBOX/";
  services.postfix.canonical = ''
    qyliss hi@alyssa.is
  '';
  services.postfix.virtual = ''
    hi@alyssa.is qyliss
  '';

  # NixOS links /var/lib/postfix/conf to /etc/postfix, but
  # postfix.service deletes /var/lib/postfix in an ExecStartPre, so we
  # can't keep files there without adding them to the store.
  #
  # Work around this with a layer of symlink indirection.
  services.postfix.mapFiles.sasl_passwd = pkgs.runCommand "sasl_passwd" {} ''
    ln -s /var/lib/postfix/sasl_passwd $out
  '';
  services.postfix.config.smtp_sasl_password_maps = "hash:/etc/postfix/sasl_passwd";

  services.postfix.config.sender_dependent_relayhost_maps = "hash:/etc/postfix/sender_dependent_relayhost";
  services.postfix.mapFiles.sender_dependent_relayhost = pkgs.writeText "sender_dependent_relayhost" ''
    @unikie.com [smtp.gmail.com]:465
  '';

  services.postfix.config.smtp_sasl_auth_enable = true;
  services.postfix.config.smtp_sasl_tls_security_options = "noanonymous";
  services.postfix.config.smtp_tls_security_level = "encrypt";
  services.postfix.config.smtp_tls_wrappermode = true;

  systemd.services.postfix-setup.unitConfig.ConditionPathExists = "/var/lib/postfix/sasl_passwd";
  systemd.services.postfix.unitConfig.ConditionPathExists = "/var/lib/postfix/sasl_passwd";
}