sending mail through c#

Mahendren Myya

i got a exception when send mail

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Must issue a STARTTLS command first. s2sm7483493pfa.167 - gsmtp

i given Host,Port No, credentials correctly, but exception will be like this.

can anyone help me..

8 Replies

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ram kumar7y ago
1. Enable SSL
2. Pass the correct user name and password
0
Ravishankar N7y ago
Hi Mahendren Myya,

Be sure to use System.Net.Mail, not the deprecated System.Web.Mail. Doing SSL with System.Web.Mail is a gross mess of hacky extensions.
using System.Net;

using System.Net.Mail;



var fromAddress = new MailAddress("[email protected]", "From Name");

var toAddress = new MailAddress("[email protected]", "To Name");

const string fromPassword = "fromPassword";

const string subject = "Subject";

const string body = "Body";



var smtp = new SmtpClient

{

    Host = "smtp.gmail.com",

    Port = 587,

    EnableSsl = true,

    DeliveryMethod = SmtpDeliveryMethod.Network,

    UseDefaultCredentials = false,

    Credentials = new NetworkCredential(fromAddress.Address, fromPassword)

};

using (var message = new MailMessage(fromAddress, toAddress)

{

    Subject = subject,

    Body = body

})

{

    smtp.Send(message);

}
0
Leon D7y ago
Hi

Check if the below solution works:
https://www.e-iceblue.com/Tutorials/Spire.Email/Spire.Email-Program-Guide/Send-Email-with-Attachment-in-C-VB.NET.html
0
Vivek Kumar7y ago
Hi,
Have a look to below link for your reference.

https://stackoverflow.com/questions/17462628/the-server-response-was-5-7-0-must-issue-a-starttls-command-first-i16sm1806350

0
Željko Perić7y ago
Hello Mahendren Myya,

I think that there are two correct values missing inside Your program :
Credential.UserName
Credential.Password

Here is code sample that I have used to send e-mail from my computer.
Mail is sent using GOOGLE SMTP server smtp.gmail.com over default port number 587.
Method uses System.Net.Mail namespace.
using System.Net.Mail
void Send_E_Mail()
        {
                string to = "Recepient mail address";
                string from = "Your mail adress";
                string subject = "Testing personal mailing system";
                string body = " This is test message sent to " + to;
                MailMessage Message = new MailMessage(from,to,subject,body);
                // GOOGLE SMTP server and port number
                SmtpClient client = new SmtpClient("smtp.gmail.com",587);
                client.EnableSsl = true;
                System.Net.NetworkCredential Credential =
                                    new System.Net.NetworkCredential();
                Credential.UserName = "Your GOOGLE account user name";
                Credential.Password = "Your GOOGLE account password";
                client.Credentials = Credential;
                try
                {
                    client.Send(Message);
                }
                catch (Exception e)
                {
                    MessageBox.Show(e.Message);
                }

        }
If there is need to use YAHOO SMTP server, just change server name to smtp.mail.yahoo.com, port number is the same.
// YAHOO SMTP server and port number
SmtpClient client = new SmtpClient("smtp.mail.yahoo.com",587);
NOTICE : Open YAHOO account, security settings and check Allow less secure apps to log in

All the best,
Željko Peric
0
Md Sarfaraj7y ago
https://myaccount.google.com/security Go to above link and on less secure app access.
0
Amit Gupta7y ago
Make sure you had EnableSsl = true in Smtp object
+1
Atul Sharma7y ago
Probably you missed providing authentication from google app.

Here are 2 simple steps to do that -
1. go to https://myaccount.google.com/u/1/lesssecureapps
it may ask for credentials if you are not logged in to the google account.

2. Here you will find this and enable from the switch.

Hope this helps.
0