switch (opt) {
case 'd': domain = optarg; break;
case 'e': sender = optarg; break;
case 'f': sfile = optarg; break;
case 'r': rev = true; break;
switch (opt) {
case 'd': domain = optarg; break;
case 'e': sender = optarg; break;
case 'f': sfile = optarg; break;
case 'r': rev = true; break;