Question

im trying to send an email using my google apps account,
and i keep getting this error:

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

when i try the same code with a normal gmail account this works.

        var msg = new MailMessage();
        msg.IsBodyHtml = true;
        msg.Subject = "subject here";
        msg.Body = "body here";
        msg.To.Add("email adress here");

        var client = new SmtpClient();
        client.EnableSsl = true;
        client.Send(msg);

Answer 1

You need to connect to Gmail’s SMTP server on port 587 and specify an SSL connection

http://support.google.com/mail/bin/answer.py?hl=en&answer=13287