public void TestSmtpConfigToXml()
        {
            var config = new MsSmtpConfig(
              "description",
              "mail.example.com",
              "user",
              "password",
              25,
              false
              );

            var xml = new XmlDocument();
            var xmlElement = xml.CreateElement("config");
            config.ToXml(xmlElement, EncryptionKey);

            Assert.AreEqual("user", xmlElement.GetAttribute("username"));
            Assert.AreNotEqual("password", xmlElement.GetAttribute("password"));
            Assert.AreEqual("password", MsStringCipher.Decrypt(xmlElement.GetAttribute("password"), EncryptionKey));
        }