Sending mail using SmtpClient in .net

Question

I am unable to send the mail using smtp client. here is the code:

SmtpClient client=new SmtpClient("Host");
client.Credentials=new NetworkCredential("username", "password");
MailMessage mailMessage = new MailMessage();
mailMessage.from="[email protected]";
mailMessage.To.Add("[email protected]");
mailMessage.body="body";
mailMessage.subject="subject";
client.Send(mailMessage);

The problem is that when I use this code in ASP.NET application, I do not recieve any mails. When in asp.net I change the from mail address to username given in NetworkCredential, I recieve mails.

But in C# windows application, I can get emails, even if sender's email address is not valid.

Thanks in advance....

Answer 1

It means your mail server does not allow Mail-Relay. Your mail server only allows you to send mail from authenticated email-id as username. Generaly this is done to prevent mails being sent as different identities other than the authenticated one.

Answer 2

try this :

{ MailMessage mail = new MailMessage("emailfrom","emailto");

        mail.From = new MailAddress("emailfrom");
        mail.Subject = txtsbjct.Text;
        string Body = txtmsg.Text;
        mail.Body = Body;

        mail.IsBodyHtml = true;
        SmtpClient smtp = new SmtpClient();
        smtp.Host = "smtp.gmail.com"; //Or Your SMTP Server Address
        smtp.Credentials = new System.Net.NetworkCredential
      ("youremail", "yourpassword");



        smtp.EnableSsl = true;
        smtp.Send(mail);
        txtemail.Text = "";
        txtmsg.Text = "";
        txtsbjct.Text = "";
        Label1.Text = "your email has been send";
        mail = null;
        smtp = null;
    }

by colonel