String fictionalDomain = "abgsfe3rsf.de";
String existingDomain = "james.apache.org";
String mail = "sender@james.apache.org";
String rcpt = "rcpt@localhost";
smtpProtocol.sendCommand(heloCommand, fictionalDomain);
smtpProtocol.setSender(mail);
smtpProtocol.addRecipient(rcpt);
// this should give a 501 code cause the helo/ehlo could not resolved
assertEquals("expected error: " + heloCommand + " could not resolved", 501, smtpProtocol.getReplyCode());