E-mail in vb.net

I am using following code to send e-mail. Below code is working fine in my server ( but when I am using it my client machine it gives proxy error.

Server has proxy setting and user-name and password for proxy are user-name=user and password=user and main login to server to start the server is log-in name=administrator and password is admin.

Please guide me to send the e-mail from my client machine.

System.Net.Mail.MailMessage mail = new System.Net.Mail.MailMessage();

mail.Subject = "subject";

mail.From = new System.Net.Mail.MailAddress("fultufatak2003@gmail.com");
mail.IsBodyHtml = true;
mail.Body = "message";

System.Net.Mail.SmtpClient smtp = new System.Net.Mail.SmtpClient("");

Prashant Trivedi.