anchor.diff:    NIX_LDFLAGS = lib.optionalString tlsSupport "-lcrypto";
   
     meta = with lib; {
  +    description = "simple MTA to deliver mail from a computer to a mail hub";
       platforms = platforms.linux;
       license = licenses.gpl2;
       maintainers = with maintainers; [ basvandijk ];
  
positive.code:     (lib.enableFeature tlsSupport "ssl")
    ];
  
    postConfigure =
      ''
        # Don't run the script that interactively generates a config file.
        # Also don't install the broken, cyclic symlink /lib/sendmail.
        sed -e '/INSTALLED_CONFIGURATION_FILE/d' \
            -e 's|/lib/sendmail|$(TMPDIR)/sendmail|' \
            -i Makefile
        substituteInPlace Makefile \
          --replace '$(INSTALL) -s' '$(INSTALL) -s --strip-program $(STRIP)'
      '';
  
    installFlags = [ "etcdir=$(out)/etc" ];
  
  
negative.code: { lib, stdenv, fetchurl, tlsSupport ? true, openssl }:
  
  stdenv.mkDerivation rec {
    pname = "ssmtp";
    version = "2.64";
  
    src = fetchurl {
      url = "mirror://debian/pool/main/s/ssmtp/ssmtp_${version}.orig.tar.bz2";
      sha256 = "0dps8s87ag4g3jr6dk88hs9zl46h3790marc5c2qw7l71k4pvhr2";
    };
  
  