Error: The SMTP server requires a secure connecton or the client was not authenticated. The server
response was: 5.7.0 Authentication Required. Learn more at.
private void SendMail(string email, string firstname)
{
MailAddress from = new MailAddress($"{email}", $"{firstname}");
MailAddress to = new MailAddress($"{email}");
MailMessage m = new MailMessage(from, to);
m.Subject = "TEST";
m.Body = "<h2>TEST</h2>";
m.IsBodyHtml = true;
SmtpClient smtp = new SmtpClient("smtp.gmail.com", 587);
smtp.Credentials = new NetworkCredential("jewralyapp#mail.ru", "password");
smtp.EnableSsl = true;
smtp.Send(m);
}
I want to send a letter to the mail, but the error that I indicated above comes out, here is the code, can you tell me what is wrong?
I see that your email is #mail.ru and the server is gmail, is that correct? I think you need to use your gmail account.
You also need enable weaker credentials on your gmail account. Forgot what they actually call it but it's on gmail security setting.
I had also faced the same problem.
Your SmtpClient is gmail, but you are using "jewralyapp#mail.ru"!!!
Make sure to set "Less secure app access" to ON in your Gmail security setting.
In my case, the problem was solved.
I have a web with contact form - I want feedback being sent to my gmail account. For this I created another, dummy gmail account for sending these messages. Code looks like this
MailMessage msg = new MailMessage();
msg.To.Add("to_mail#gmail.com");
msg.From = new MailAddress("from_mail#gmail.com");
msg.Subject = "Feedback";
msg.Body = txtName.Text + " " + txtEmail.Text + " " + txtMessage.Text;
msg.IsBodyHtml = true;
SmtpClient client = new SmtpClient();
client.Host = "smtp.gmail.com";
client.Port = 587;
client.UseDefaultCredentials = false;
client.Credentials = new System.Net.NetworkCredential("from_mail#gmail.com", "password");
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.EnableSsl = true;
client.Send(msg);
This code works fine when I run it from localhost from my VS project, but once I compile it and upload to the web, its stops working with this error.
System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required.
Does anyone have an idea what caused it and how to fix it? I already enabled access for less secure applications in my gmail account. Tried also 465 port, but that doesnt work either.
Thank a lot, Jozef
Finally found an answer. Had to click this link with my "From" Gmail account logged in.
https://accounts.google.com/b/0/DisplayUnlockCaptcha
Possible Reason:
In gmail, If the current login region and the previous login region is
different, then gmail ask us some security questions before login. So
better try to login once via browser in the system which you are using
that C# app.
I am currently using Google Apps to send SMTP e-mails. If my project deploys some of the information that i am going to be sending will be confidential and i would like to make sure the transmission is secure. Can anyone please let me know what i need to do to ensure that i send a safe e-mail using smtp through the google apps smtp server? smtp.google.com.
Any help greatly appreciated.
From what I have been told i need to force Https and have a SSL cert in order to do this. I don't know if this is true?
You Can Use 'smtp.EnableSsl = true' For Enable SSL for security.
MailMessage mail = new MailMessage();
mail.To.Add("" + to + "");
mail.From = new MailAddress("" + from + "");
mail.Subject = "Email using Gmail";
string Body = "Hi, this mail is to test sending mail" +
"";
mail.Body = Body;
mail.IsBodyHtml = true;
Attachment at = new Attachment(Server.MapPath("~/ExcelFile/TestCSV.csv"));
mail.Attachments.Add(at);
mail.Priority = MailPriority.High;
SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com"; //Or Your SMTP Server Address
smtp.Credentials = new System.Net.NetworkCredential(""+ username +"", ""+ password +"");
smtp.EnableSsl = true;
smtp.Port = 587;
smtp.Send(mail);
To enforce Network Security you have to use SSL. to enforce security of the data going from your webserver to mail server you need to send your mail over SSL. and to secure the HTTP request that triggers the mail action you need to enforce SSL over HTTP.
But the question is Security in what context ? If you need network security to ensure a 3rd party cannot eavesdrop or manipulate then SSL is your way to go.
I cannot figure out for the life of my why this isn't working
SmtpClient smtp = new SmtpClient
{
Host = "smtp.gmail.com",
Port = 587,
UseDefaultCredentials = false,
DeliveryMethod = SmtpDeliveryMethod.Network,
Credentials = new NetworkCredential("myemail#gmail.com", "myGmailPasswordHere"),
EnableSsl = true,
Timeout = 10000
};
smtp.Send(mail);
I get:
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required.
I just specified EnableSsl to true so that shouldn't be the issue in terms of secure connection.
I'm running this from localhost. And yes, my username and password I'm entering to auth (my gmail account credentials) is 100% right.
I know this is an old topic, BUT... Google has changed something on their security settings.
Was struggling with all the answers until I checked my email with a mail from Google stating that "we've recently blocked a sign-in attempt on your Google account".
That led me to this page:
Google Account Security
Under the "Access for less secure apps" section, you can enable access to your account from other devices/applications... like your C# application.
Note, there is no longer an "application specific" section.
Hope this helps someone... I just lost 30 minutes of my life...
If login info is 100% right, you need to set UseDefaultCredentials = false first and then set the credentials you want to use Credentials = new NetworkCredential("myemail#gmail.com", "myGmailPasswordHere").
If you set the credentials first, when you set UseDefaultCredentials = false this will make the Credentials property to null.
This is wired, but it happened to me.
Debug your code and check if the Credentials property is null before you call smtp.Send(message);. If so, then try inverting the order. It seems you have it in the right order, but if it's null, don't use the inline initialization.
Hope it helps.
EDIT: If you are using two-step verification, be sure you are using an App Specific password
It looks like Gmail requires Application-specific password(not your main password).
Please, look into this: http://support.google.com/mail/bin/answer.py?hl=en&answer=1173270
I had the same problem recently.
This worked just fine for me
SmtpClient smtp = new SmtpClient
{
Host = "smtp.gmail.com",
Port = 587,
UseDefaultCredentials = false,
DeliveryMethod = SmtpDeliveryMethod.Network,
Credentials = new NetworkCredential("myid#gmail.com", "mypassword"),
EnableSsl = true,
Timeout = 10000
};
MailMessage message = new MailMessage();
message.Body = "hello there";
message.Subject = "hi!!";
message.To.Add("myid#gmail.com");
message.From = new MailAddress("myid#gmail.com");
smtp.Send(message);
I had this problem before and fixed it by following these steps:
Go to "My Account" settings.
Click "Sign-in & Security" category.
Scroll down to "Connected apps & sites" section.
turn off the "Allow less secure apps" option.
I just turned this option off and my code ran successfully.
For me the solution required 2 "steps":
set UseDefaultCredentials = false first, then set the credentials I want to use Credentials = new NetworkCredential("myemail#gmail.com", "myGmailPasswordHere"). Setting the credentials first, when I set UseDefaultCredentials = false will make the Credentials property null.
Allow less secure apps on my Google profile.
Have a callback as follows. Tell System.Net to ignore the error!
Add this before call to Send()
ServicePointManager.ServerCertificateValidationCallback =
delegate(object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
{ return true; };
smtp.Send(mail);
<mailSettings>
<smtp from="youremail#gmail.com">
<network host="smtp.gmail.com" password="yourpassword" port="587" userName="username"/>
</smtp>
</mailSettings>
Edit: try adding this line smtp.Credentials = Credentials after this
Credentials = new NetworkCredential("myemail#gmail.com", "myGmailPasswordHere"),
Had the same issue accessing smtp.gmail.com from an ASP.NET application running on Amazon AWS hosting. It turned out that my configuration was right - it was also working fine from another computer - but gmail would deny my login attempt, because I try logging in from an unusual location.
I logged on to gmail over the web interface (www.gmail.com), and had to answer a captcha. After that it worked.
My problem was that the domain-owner for our gmail-account had disabled both "Access for less secure apps" and two step authentication. There was no way to enable it, I couldn't even see the setting. So I tested with my personal account instead, and it worked fine.
Very simple just follow this for C# WPF Application:
private void SendByGmail(string subject, string body, string recepientEmail, string MailMsgFrom, string MailMsgPass)
{
using (MailMessage mailMessage = new MailMessage())
{
mailMessage.From = new MailAddress(MailMsgFrom);
mailMessage.Subject = subject;
mailMessage.Body = body;
mailMessage.IsBodyHtml = true;
mailMessage.To.Add(new MailAddress(recepientEmail));
mailMessage.Priority = System.Net.Mail.MailPriority.High;
SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com";
smtp.EnableSsl = true;
smtp.Timeout = 200000;
System.Net.NetworkCredential NetworkCred = new System.Net.NetworkCredential();
NetworkCred.UserName = MailMsgFrom;
NetworkCred.Password = MailMsgPass;
smtp.UseDefaultCredentials = true;
smtp.Credentials = NetworkCred;
smtp.Port = 587;
smtp.Send(mailMessage);
}
}
After that you should get like this Error
smtpException {"The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required. Learn more at"} System.Net.Mail.SmtpException
To Solve this problem, at first login your email account to your google account in web browser. Then just follow this link Google Account Activity. Then you'll get recent Devices & activity by your account. If show block your current activity from your current device. Just Unblock this. Then try again to send email. Thanks
I am using .net version 3.5 for sending mails though my web application
I get the following 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
What could be causing this?
Source from here http://www.systemnetmail.com/faq/4.2.aspx
//create the mail message
MailMessage mail = new MailMessage();
//set the addresses
mail.From = new MailAddress("me#mycompany.com");
mail.To.Add("you#yourcompany.com");
//set the content
mail.Subject = "This is an email";
mail.Body = "this is the body content of the email.";
//send the message
SmtpClient smtp = new SmtpClient("127.0.0.1");
//to authenticate we set the username and password properites on the SmtpClient
smtp.Credentials = new NetworkCredential("username", "secret");
smtp.Send(mail);
EDIT: This error means what it's written: smtp server needs authentication information (username and password). So, you need set SmtpClient.Credentials.
Try:
smtpclient.EnableSsl = true;
The SMTP server requires a secure
connection or the client was not
authenticated. The server response
was: 5.7.1 Client was not
authenticated
so you need to authenticate by adding credentials
smtpClient.Credentials = new NetworkCredential("username", "password");