SMTP authentication with .NET fails

Question

Hello i am having some problems sending mails thoug my site.

I keep getting the error

The SMTP server requires a secure connection or the client was not authenticated. The server response was: SMTP authentication is required.

My Web.config have

<system.net>
    <mailSettings>
        <smtp from="[email protected]">
            <network host="mail.XXXXX.XX" port="25" userName="[email protected]" password="XXXXXXXX" defaultCredentials="true" />
        </smtp>
    </mailSettings>
</system.net>

And my code

            MailMessage message = new MailMessage();
            message.From = new MailAddress("[email protected]");
            message.To.Add(new MailAddress(split[0]));
            message.Subject = split[1];
            message.Body = ContactUsBody(model);
            message.IsBodyHtml = true;

            SmtpClient client = new SmtpClient();
            client.Send(message);

It throws the error on client.Send(message), i think that for some reason it dose not use the password and username from the config. I have tried logging on to the email account though thunderbird and have no problems sending or receiving mails there. What am i doing wrong here?

Oskar Kjellin Oskar Kjellin · Accepted Answer · 2011-07-20T12:46:38

It does not use the credentials that you've provided because you have set it to use default credentials.

Try this:

<system.net>
    <mailSettings>
        <smtp from="[email protected]" deliveryMethod="network">
            <network host="mail.XXXXX.XX" port="25" userName="[email protected]" password="XXXXXXXX" defaultCredentials="false" />
        </smtp>
    </mailSettings>
</system.net>

SMTP authentication with .NET fails

1 Answers