Sending Mail using gmail SMTP from CSharp/.net

Question

using(SmtpClient client = new SmtpClient("smtp.gmail.com", 587)) 
{
    // Configure the client
    client.EnableSsl = true;
    client.UseDefaultCredentials = false;
    client.Credentials = new NetworkCredential(textBox1.Text, textBox3.Text);

    client.DeliveryMethod = SmtpDeliveryMethod.Network;
    MailMessage message = new MailMessage(
    textBox1.Text, // From field
    textBox2.Text, // Recipient field
    textBox4.Text, // Subject of the email message
    richTextBox1.Text // Email message body
    );

    client.Send(message);

    MessageBox.Show("Email has been sent.");
}

Error: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required.

I have been getting this error with gmail but am able to use other SMTP Servers to send mails. The credentials are correct.

read this link: http://email.about.com/od/gmailtips/qt/How-To-Unlock-Gmail-For-A-New-Email-Program-Or-Service.htm — Zohar Peled, Mar 25 '15 at 09:08
Check this. http://stackoverflow.com/questions/704636/sending-email-through-gmail-smtp-server-with-c-sharp — Ramesh Durai, Mar 25 '15 at 09:08
@ZoharPeled The link worked and am able to send the mails..Thanks — sooraj, Mar 25 '15 at 09:14
I had done using PHP and was working fine without doing those steps... — sooraj, Mar 25 '15 at 09:15

score 5 · Answer 1 · edited Mar 25 '15 at 09:08

5

Looks like there is a security issue with Gmail account.

I have also faced that same issue and then found solution from this post.

The post mentioned that you need to change the Account Permission setting with "Access of Less secure App" Enabled.

In fact you will get notification when you logged in to your gmail account.

edited Mar 25 '15 at 09:08

Jenish Rabadiya

6,708
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answered Mar 25 '15 at 09:06

Jinesh Jain

1,232
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I have the same problem, but your solution doesn't resolve my problem.. When i send mail, the service is not aviable, sorry for my bad english – Nopesound Feb 12 '16 at 06:41

score 3 · Answer 2 · answered Mar 13 '16 at 11:20

    message.To.Add(new MailAddress("abc@abc.com));  // replace with valid value 
        message.From = new MailAddress("abc@abc.com", "Contact Form");
        message.Subject = Subject;
        message.Body = string.Format(NewBody);
        message.IsBodyHtml = true;
        using (var smtp = new SmtpClient())
        {
            var credential = new NetworkCredential
            {
                UserName = "abc@gmail.com",  // replace with valid value
                Password = "qwerty123456"  // replace with valid value
            };
            smtp.Credentials = credential;
            smtp.Host = "smtp.gmail.com";
            smtp.Port = 587;
            smtp.EnableSsl = true;
            smtp.Send(message);
        }

Just This is working code for me you can use it,Only Problem with this code is sometime mails are coming in spam Folder.

It would help to specify what "valid value" means; what password is used in NetworkCredential.Password; is it the Google password or the email account password? — Sam Hobbs, Feb 16 '17 at 18:01

score 0 · Answer 3 · answered May 30 '17 at 11:13

0

You need to enable two step authentication for you Gmail account and get application password. Then use that password instead of regular one.

answered May 30 '17 at 11:13

S. Surkov

1

Hi Surkov. When you post an answer you should also explain HOW to do it not just WHAT to do. – Noel Widmer May 30 '17 at 11:14

Sending Mail using gmail SMTP from CSharp/.net

3 Answers3

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