Question

I have test this code on my development environment (windows 7, visual studio 2010) and it works grate

public static bool SendMail(string to, string subject, string message)
{
    try
    {
        NetworkCredential loginInfo = new NetworkCredential("mylogin","mypassowrd");
        MailMessage msg = new MailMessage();
        msg.From = new MailAddress("mylogin");
        msg.To.Add(new MailAddress(to));
        msg.Subject = subject;
        msg.Body = message;
        msg.IsBodyHtml = true;
        SmtpClient client = new SmtpClient("smtp.gmail.com",587);
        client.EnableSsl = true;
        client.UseDefaultCredentials = false;
        client.Credentials = loginInfo;
        client.Send(msg);

        return true;
    }
    catch (Exception)
    {
        return false;
    }
}

But when I move it to my production server (windows server 2008) it’s not working. My initial thoughts was that the firewall is blocking the port, so I create an Outbound Rule to open the port 587 with TCP protocol. Bot this doesn’t work.

Any insight will be appreciated.

Thanks

Answer 1

Did you verify that you can reach port 587 on smtp.gmail.com from some other tool on the server? In a production environment there are numerous places where a port can be filtered – including firewalls and routers in the network and not only the firewall on the server.

One way to verify network connectivity of the application is to try to send a mail in your application and on the same time run the command netstat -n on the console of the server. If the connection to smtp.gmail.com get stuck as SYN_SENT no TCP connection is established.