anchor.diff:          s:^# \(SUPPORT_SPF\)=.*:\1=yes:
           s:^# \(LDFLAGS += -lspf2\):\1:
         ''}
  +      ${stdenv.lib.optionalString enableDMARC ''
  +        s:^# \(SUPPORT_DMARC\)=.*:\1=yes:
  +        s:^# \(LDFLAGS += -lopendmarc\):\1:
  +      ''}
         #/^\s*#.*/d
         #/^\s*$/d
       ' < src/EDITME > Local/Makefile
  
positive.code:     ++ stdenv.lib.optionals enableMySQL [ libmysqlclient zlib ]
      ++ stdenv.lib.optional enableAuthDovecot dovecot
      ++ stdenv.lib.optional enablePAM pam
      ++ stdenv.lib.optional enableSPF libspf2;
  
    preBuild = ''
      sed '
  
negative.code: , enableAuthDovecot ? false, dovecot
  , enablePAM ? false, pam
  , enableSPF ? true, libspf2
  , enableDMARC ? true, opendmarc
  }:
  
  stdenv.mkDerivation rec {
  