send email with EnableSSL= true throw AuthenticationException - email

Question

I used the following code to send my email with EnableSsl = true,the throw the following exception:
System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, Exception exception)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
public static void SendEmailBySmtpServer(int currentSendCount)
{
try
{
var emailBodyJson = "Period Send Email From Service at -" + DateTime.Now +" Times="+currentSendCount;
emailBodyJson += " EnableSsl=" + ConfigurationManager.AppSettings["SmtpServer.EnableSsl"];
NameValueCollection appSettings = ConfigurationManager.AppSettings;
string fromEmailAddress = appSettings["SmtpServer.FromEmailAddress"];
string toEmailAddress = appSettings["SmtpServer.UserFeedback.ToEmailAddress"];
string host = appSettings["SmtpServer.Host"];
var smtpClient = new SmtpClient(host);
var message = new MailMessage();
message.From = new MailAddress(fromEmailAddress);
message.To.Add(new MailAddress(toEmailAddress));
message.Subject = emailBodyJson;
message.IsBodyHtml = true;
message.Body = emailBodyJson;
smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
smtpClient.EnableSsl = Convert.ToBoolean(appSettings["SmtpServer.EnableSsl"]);//if this changed to true then send failed
smtpClient.UseDefaultCredentials = true;
smtpClient.Send(message);
logger.Info("Send Email Count = "+currentSendCount);
}
catch (Exception ex)
{
logger.Error(ex);
}

Answer 1

To send an email you can use the following code, its working, But you have to use the appropriate .jar files.
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
public class Email {
private static String USER_NAME = "xxxx"; // GMail user name (just the part before "#gmail.com")
private static String PASSWORD = "xxxxx"; // GMail password
private static String RECIPIENT = "xxxxx#xxxx.com";
public static void main(String[] args) {
String from = USER_NAME;
String pass = PASSWORD;
String[] to = { RECIPIENT }; // list of recipient email addresses
String subject = "Java send mail example";
String body = "hi ..this is a test mail,!";
sendFromGMail(from, pass, to, subject, body);
}
private static void sendFromGMail(String from, String pass, String[] to, String subject, String body) {
Properties props = System.getProperties();
String host = "smtp.gmail.com";
// String host="localhost";
// props.put("mail.smtp.ssl.trust", "smtp.gmail.com");
props.put("mail.smtp.starttls.enable", "true");
// props.put("mail.smtp.host", host);
props.put("mail.smtp.ssl.trust", host);
props.put("mail.smtp.user", from);
props.put("mail.smtp.password", pass);
props.put("mail.smtp.port", "587");//587
props.put("mail.smtp.auth", "true");
//System.out.println("success point 1");
Session session = Session.getDefaultInstance(props);
MimeMessage message = new MimeMessage(session);
try {
// System.out.println("success point 2");
message.setFrom(new InternetAddress(from));
InternetAddress[] toAddress = new InternetAddress[to.length];
// To get the array of addresses
for( int i = 0; i < to.length; i++ ) {
toAddress[i] = new InternetAddress(to[i]);
}
for( int i = 0; i < toAddress.length; i++) {
message.addRecipient(Message.RecipientType.TO, toAddress[i]);
}
//System.out.println("success point 3");
message.setSubject(subject);
message.setText(body);
// System.out.println("success point 4");
Transport transport = session.getTransport("smtp");
// System.out.println("success point 5");
transport.connect(host, from, pass);
transport.sendMessage(message, message.getAllRecipients());
transport.close();
// System.out.println("success 6");
}
catch (AddressException ae) {
ae.printStackTrace();
}
catch (MessagingException me) {
me.printStackTrace();
}
}
}