This is my first post on Stack, and I've literally just started programming, so please, be patient.
I'm attempting to send an email to "x" email address when Button 1 is pressed. I've looked around, and every thread is jargon-heavy and not in my context. Please pardon me if this is a "newb' question, or if it's already thouroughly answered somewhere else.
The error I'm getting is "
Failure sending mail. ---> System.IO.IOException: Unable to read data from the transport connection: net_io_connectionclosed."
Here's my code
using (SmtpClient smtp = new SmtpClient())
{
smtp.Host = "smtp.gmail.com";
smtp.Port = 465;
smtp.Credentials = new NetworkCredential("myemail", "mypassword");
string to = "toemail";
string from = "myemail";
MailMessage mail = new MailMessage(from, to);
mail.Subject = "test test 123";
mail.Body = "test test 123";
try
{
smtp.Send(mail);
}
catch (Exception ex)
{
Console.WriteLine("Exception caught in CreateTestMessage2(): {0}",
ex.ToString());
}
Any help is greatly appreciated!
The error you're getting could come from a plethora of things from a failed connection, to the server rejecting your attempts, to the port being blocked.
I am by no means an expert on SMTP and its workings, however, it would appear you are missing setting some of the properties of the SmtpClient.
I also found that using port 465 is a bit antiquated, and when I ran the code using port 587, it executed without an issue. Try changing your code to something similar to this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.Mail;
using System.Net;
namespace EmailTest
{
class Program
{
static void Main(string[] args)
{
SendMail();
}
public static void SendMail()
{
MailAddress ma_from = new MailAddress("senderEmail#email", "Name");
MailAddress ma_to = new MailAddress("targetEmail#email", "Name");
string s_password = "accountPassword";
string s_subject = "Test";
string s_body = "This is a Test";
SmtpClient smtp = new SmtpClient
{
Host = "smtp.gmail.com",
//change the port to prt 587. This seems to be the standard for Google smtp transmissions.
Port = 587,
//enable SSL to be true, otherwise it will get kicked back by the Google server.
EnableSsl = true,
//The following properties need set as well
DeliveryMethod = SmtpDeliveryMethod.Network,
UseDefaultCredentials = false,
Credentials = new NetworkCredential(ma_from.Address, s_password)
};
using (MailMessage mail = new MailMessage(ma_from, ma_to)
{
Subject = s_subject,
Body = s_body
})
try
{
Console.WriteLine("Sending Mail");
smtp.Send(mail);
Console.WriteLine("Mail Sent");
Console.ReadLine();
}
catch (Exception ex)
{
Console.WriteLine("Exception caught in CreateTestMessage2(): {0}",
ex.ToString());
Console.ReadLine();
}
}
}
}
Tested to work as well. Also of note: if your Gmail account does not allow "Less Secure" apps to access it, you'll get an error and message sent to your inbox stating an unauthorized access attempt was caught.
To change those settings, go here.
Hope this helps, let me know how it works out.
Related
Below is the code I'm using. Please advise on how this can be rectified.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Net;
using System.Net.Mail;
public partial class mailtest : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void SendEmail(object sender, EventArgs e)
{
lblmsg.Text = "";
try
{
using (MailMessage mm = new MailMessage(txtEmail.Text, txtTo.Text))
{
mm.Subject = txtSubject.Text;
mm.Body = txtBody.Text;
//if (fuAttachment.HasFile)
//{
// string FileName = Path.GetFileName(fuAttachment.PostedFile.FileName);
// mm.Attachments.Add(new Attachment(fuAttachment.PostedFile.InputStream, FileName));
//}
mm.IsBodyHtml = false;
SmtpClient smtp = new SmtpClient();
smtp.Host = txtsmtphost.Text.Trim();
smtp.EnableSsl = false;
if (chkssl.Checked == true)
{
smtp.EnableSsl = true;
}
NetworkCredential NetworkCred = new NetworkCredential(txtEmail.Text, txtPassword.Text);
smtp.UseDefaultCredentials = true;
smtp.Credentials = NetworkCred;
smtp.Port = int.Parse(txtport.Text);
smtp.Send(mm);
lblmsg.ForeColor = System.Drawing.Color.DarkGreen;
lblmsg.Text = "Email sent successfuly !!";
//ClientScript.RegisterStartupScript(GetType(), "alert", "alert('Email sent successfuly !!');", true);
}
}
catch (Exception ex)
{
lblmsg.ForeColor = System.Drawing.Color.Red;
lblmsg.Text = "Failed " + ex.ToString();
ClientScript.RegisterStartupScript(GetType(), "alert", "alert('Failed');", true);
}
}}
The error message is:
System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Authentication Required. Learn more at at System.Net.Mail.MailCommand.CheckResponse(SmtpStatusCode statusCode, String response) at System.Net.Mail.MailCommand.Send(SmtpConnection conn, Byte[] command, MailAddress from, Boolean allowUnicode) at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception) at System.Net.Mail.SmtpClient.Send(MailMessage message)
Since this question keeps coming up as the first on Google, what today worked for me (11 June 2022) is what I will share. This question has been asked many times in similar way and many different things have worked for many people, but that stops now, there are no work around in "code" anymore (assuming your code is perfect but throwing exception as written in the title above)! Why because Google made a change (from https://support.google.com/accounts/answer/6010255):
Less secure apps & your Google Account:
To help keep your account secure, from May 30, 2022, Google no longer supports the use of third-party apps or devices which ask you to sign in to your Google Account using only your username and password.
Important: This deadline does not apply to Google Workspace or Google Cloud Identity customers. The enforcement date for these customers will be announced on the Workspace blog at a later date.
Now what do you do, its simpler then you think, go to https://myaccount.google.com/, Click "Security", enable Two-step Verification, once done, come back to the myaccount Security page, you will see "App passwords", open that, it will give you options for what you are trying to make a password for (a bunch of devices), select "Windows Computer", make a password, copy it, use this password in the NetworkCredential class object in your code, and your emails should start working again through Code.
This wasted so much of my hours yesterday, my Winforms app was working perfect till a couple days back it stopped sending emails.
The SMTP server requires a secure connection or the client was not authenticated.
To fix this error Go to your google account and generate an apps password
When running your code use the password generated instead of the actual users password.
This happens most often when the account has 2fa enabled.
Example with SmtpClient
using System;
using System.Net;
using System.Net.Mail;
namespace GmailSmtpConsoleApp
{
class Program
{
private const string To = "test#test.com";
private const string From = "test#test.com";
private const string GoogleAppPassword = "XXXXXXXX";
private const string Subject = "Test email";
private const string Body = "<h1>Hello</h1>";
static void Main(string[] args)
{
Console.WriteLine("Hello World!");
var smtpClient = new SmtpClient("smtp.gmail.com")
{
Port = 587,
Credentials = new NetworkCredential(From , GoogleAppPassword),
EnableSsl = true,
};
var mailMessage = new MailMessage
{
From = new MailAddress(From),
Subject = Subject,
Body = Body,
IsBodyHtml = true,
};
mailMessage.To.Add(To);
smtpClient.Send(mailMessage);
}
}
}
You should enable the less secure app settings on the Gmail account you are using to send emails. You can use this Link to enable the settings.
More information about your problem here.
I have a piece of code sending out account activation emails with a link in it using SMTP. My code connects to my mail box on an email provider and sends out mails. The first few mails went through. And then they started failing. Obviously they were blocked as spams.
My question is then how can I test my code? People suggest to alter the configurations of the mail server. But since I am using a 3rd party email provider, I have no control over it.
My website production server is on AWS but I can't use that for my testing.
Here is a snippet of my code. Pretty standard.
using (var msg = new MailMessage())
{
msg.From = new MailAddress(From);
msg.Subject = subject;
msg.Body = body;
msg.IsBodyHtml = true;
msg.To.Add(toEmail);
string error = "";
try
{
using (var client = new SmtpClient(SMTPServer))
{
client.UseDefaultCredentials = false;
client.Credentials = new NetworkCredential(SMTPUserName, SMTPPassword);
client.Send(msg);
}
}
catch (SmtpFailedRecipientException se)
{
error = $"Unable to mail to {toEmail}";
}
catch (SmtpException se)
{
error = "Mail server connection failed.";
}
catch (Exception ex)
{
error = "Email failed";
}
return error;
}
SmtpException is thrown and no mails are sent/received.
The Subject is Blah blah Account Activation and the Body is Please use the following link to activate your account: <a href='blah blah blah'></a>.
I need to send email using NTLM, currently, I'm using the following code to send email
SmtpClient objSmtpClient;
System.Net.NetworkCredential objNetworkCredential;
objSmtpClient = new SmtpClient("10.xxx.xxx.xxx", 587);
objSmtpClient.EnableSsl = true;
objNetworkCredential = new System.Net.NetworkCredential(userName, password);
try
{
string to = txtto.Text;
MailMessage objMailMessage = new MailMessage();
objMailMessage.From = new MailAddress("from#email.com", "sendername");
objMailMessage.To.Add(new MailAddress("to#email.com"));
objMailMessage.Subject = "subject";
objMailMessage.Body = "body";
objMailMessage.IsBodyHtml = true;
objSmtpClient.EnableSsl = true;
objSmtpClient.UseDefaultCredentials = true;
objSmtpClient.Credentials = objNetworkCredential;
objSmtpClient.Send(objMailMessage);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message + " INNER EXCEPTION > "+ex.InnerException +" DATA > "+ex.Data);
}
The Above code works if I try to change the port to 25 and EnableSSL to false, But when I try to send it using 587 and setting EnableSSL to true it doesn't work.
I'm getting the following error, sometimes I get an Invalid Certificate error.
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 Client was not authenticated.
I am also getting this error
I think the problem is with Authentication, how can I force to use NTLM
I talked with the IT team they installed a tool on my pc to check email, using that tool email was sent successfully.
The following are the setting which he applied in that tool
Can someone please help
I was testing, I had the same problem, I fixed it by disabling SSL security
SC.EnableSsl = false;
I am getting error "operation time out"and it throws me to the exception when i am sending email through my smtp server.I am using the code with gmail smtp and the same code works fine.In smtp details I am using network credential as my username and password i got when i created my email account on my domain and outgoing server and smtp port. following is my code..
protected void send_Click(object sender, EventArgs e)
{
string to = "xyz#gmail.com"; //To address
string from = "xyz#gmail.com"; //From address
MailMessage message = new MailMessage(from, to);
string mailbody = "Welcome to gmail...";
message.Subject = "Sending Email";
message.Body = mailbody;
message.IsBodyHtml = true;
SmtpClient client = new SmtpClient("server host",port);
System.Net.NetworkCredential basicCredential1 = new
System.Net.NetworkCredential("Username ","Password");
client.EnableSsl = true;
//client.Timeout = 10000;
client.UseDefaultCredentials =false;
client.Credentials = basicCredential1;
try
{
client.Send(message);
}
catch (Exception ex)
{
throw ex;
}
}
Because you haven't posted any log data, what you have already tried, and what didn't work, and only giving us the timeout as an outcome, there are a lot of open ended questions to your question. So instead of a specific answer, all I can do is give you vague directions what you need to do, to resolve your issue.
There can be a lot of issues with this sort of thing.
You write that this code performs correctly with another server, if I understand you correctly?
I would check:
A, Am I 100% sure my server connection string is correct? Also port wise?
B, Am I sure the ports are open for this communication to happen?(Check the firewalls are open)
C, Am I that there isn't some sort of version or configuration that is different between the gmail smtp, and you local smtp?
D, Check the SMTP server logs, if you are even receiving the request.
D1, if you are receiving, check which error is causing the timneout, this will likely be in the log.
D2, Start from A, There is something wrong with your connection to the SMTP server.
I've been banging my head against this one for weeks, but today was the day I promised I'd get it fixed. So far I've failed.
I am trying to send an email from a hosted MVC application, via a Hosted Exchange server. The IT department has said and confirmed that they have allowed the IP of the MVC application through. However, the following code gives me "An attempt was made to access a socket in a way forbidden by its access permissions ###.###.###.###:25" every time.
ActionResult Test()
{
MailMessage message = new MailMessage();
message.From = new MailAddress("valid.email.address");
message.Subject = "Test Email";
message.To.Add(new MailAddress("another.valid.email.address"));
message.Body = "Hey, this is a test!";
using (SmtpClient client = new SmtpClient())
{
client.Credentials = new System.Net.NetworkCredential("username", "password");
client.Port = 25;
client.EnableSsl = true; // Either true or false gives same result
client.Host = "actual.host.url";
try
{
client.Send(message);
}
catch (Exception ex)
{
ViewBag.LogMessage = string.Format("Error: {0}<br />{1}<br />{2}", ex.Message, ex?.InnerException.Message, ex?.InnerException?.InnerException.Message);
return View();
}
ViewBag.LogMessage = string.Format("client.Host: {0}<br />Client.Port: {1}<br />Client.EnableSsl: {2}<br />message.To[0].Address: {3}", client.Host, client.Port, client.EnableSsl ? "true" : "false", message.To[0].Address);
}
return View();
}
The value of the LogMessage is:
Error: Failure sending mail.
Unable to connect to the remote server
An attempt was made to access a socket in a way forbidden by its access permissions ###.###.###.###:25
Any suggestions would be welcome! I've tried port 587 with no luck. I've tried with and without credentials, with or without SSL, username matching from address or not. I've run out of things to try.
Thanks!
Try the following code, the first line tells SMTP Client to ignore any issue with the SSL cert if its provide from an invalid provider.
ServicePointManager.ServerCertificateValidationCallback =(sender,certificate, chain, sslPolicyErrors) => true;
var smtpClient = new SmtpClient("oba.exchangeserver.com")
{
Port = 587,
EnableSsl = true,
Credentials =
new NetworkCredential("username","password")
};
return smtpClient;