Try with below code it working fine.
MailMessage message = new MailMessage();//Not set from and to address here.
SmtpClient smtpClient = new SmtpClient();//Not set Host name here.
string msg = string.Empty;
try
{
MailAddress fromAddress = new MailAddress("eksamensprojekt2014.gmail.com");
message.From = fromAddress;
message.To.Add("gymjoy@hotmail.com");
message.Subject = "Test";
message.IsBodyHtml = true;
message.Body = "Test";
smtpClient.Host = "smtp.gmail.com"; // We use gmail as our smtp client
smtpClient.Port = 587;
smtpClient.EnableSsl = true;
smtpClient.UseDefaultCredentials = true;
smtpClient.Credentials = new System.Net.NetworkCredential("eksamensprojekt2014.gmail.com", "*******");
smtpClient.Send(message);
msg = "Successful<BR>";
}
catch (Exception ex)
{
msg = ex.Message;
}