The SMTP server requires a secure connection or the client was not authenticated. if uploading on godaddy

Question

below code is working fine in local, but if upload upload it on godaddy it is not working.

Error: showing

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

Line 53:        
Line 54:         smtp.EnableSsl = true;
Line 55:         smtp.Send(message);
Line 56: 
Line 57: 

plz check below code

    MailMessage message = new MailMessage();
    message.From = new MailAddress(emailid.Text);

    message.To.Add(new MailAddress("[email protected]"));

    message.Subject = "NaatKhawan's Feedback";

    message.Body = "Selected: " + DropDownList1.Text.ToString() + "<br/><br/>Name: " + name.Text.ToString() + " <br/><br/>Email: " + emailid.Text.ToString() + " <br/><br/>Contact Number: " + phone.Text.ToString() + " <br/><br/>Message:<br/> " + remabox.Text.ToString();

    message.IsBodyHtml = true;

    // finaly send the email:
    SmtpClient smtp = new SmtpClient();
    smtp.Host = "smtp.gmail.com";

    smtp.Port = 587;
    smtp.Credentials = new System.Net.NetworkCredential("[email protected]", "123");

    smtp.EnableSsl = true;
    smtp.Send(message);
    lbltxt.Visible = true;
    name.Text = "";
    emailid.Text = "";
    phone.Text = "";
    remabox.Text = "";

    lbltxt.Text = "Thank you for supporting NaatKhawan";

Answer 1

you should enable application to access gmail account. This link will help you

Answer 2

I have the same problem.

I have found this solution:

Google may block sign in attempts from some apps or devices that do not use modern security standards. Since these apps and devices are easier to break into, blocking them helps keep your account safer.

Some examples of apps that do not support the latest security standards include:

The Mail app on your iPhone or iPad with iOS 6 or below The Mail app on your Windows phone preceding the 8.1 release Some Desktop mail clients like Microsoft Outlook and Mozilla Thunderbird Therefore, you have to enable Less Secure Sign-In in your google account.

After sign into google account, go to:

https://www.google.com/settings/security/lesssecureapps