C# – How to send email from Asp.net Mvc-3

How to send a mail through mvc-3 asp.net using c#?

I have to send a forgot password so how can I do this?
My code is below.

Model code..

 using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;

namespace TelerikLogin.Models.ViewModels
{
    public class ForgotPassword
    {
        public int user_id { get; set; }
        public string user_login_name { get; set; }
        public string user_password { get; set; }

        [Required]
        [Display(Name="Email Address : ")]
        public string user_email_address { get; set; }
    }
}

Controller code..

  public ActionResult ForgotPassword()
        {
            return View();
        }

        [HttpPost]
        public ActionResult ForgotPassword(string user_email_address)
        {
            SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MVC3\TelerikLogin\TelerikLogin\App_Data\Login.mdf;Integrated Security=True;User Instance=True");

            DataTable dt1 = new DataTable();

            string strQuery = string.Format("SELECT user_password FROM [user_master] WHERE user_email_address='{0}'",user_email_address);
            conn.Open();
            SqlDataAdapter da1 = new SqlDataAdapter(strQuery, conn);
            da1.Fill(dt1);
            conn.Close();

            if (dt1.Rows.Count > 0)
            {

MailMessage msg = new MailMessage();

            msg.From = new MailAddress("abc@gmail.com");
            msg.To.Add(user_email_address);
            msg.Subject = "Password";
            msg.Body = "Test1";
            msg.Priority = MailPriority.High;

            SmtpClient client = new SmtpClient();




            client.Credentials = new NetworkCredential("abc@gmail.com", "dip", "smtp.gmail.com");
            client.Host = "smtp.gmail.com";
            client.Port = 587;
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            client.EnableSsl = true;
            client.UseDefaultCredentials = true;

            client.Send(msg);


               return RedirectToAction("About", "Home");
            }
            return View();
        }

Here I fetched the password of user from database through entered email address..

View code..

<% using (Html.BeginForm("ForgotPassword", "Account", FormMethod.Post))
   { %>

   <%: Html.LabelFor(m => m.user_email_address) %>
   <%: Html.TextBox("user_email_address")%>
      <%: Html.ValidationSummary(true) %>

<input type="submit" value="Submit"/>

   <%} %>

It gives me an error on these line

 client.Send(msg);

Error messege is:

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Must issue a STARTTLS command first. x1sm1264662igc.16

How to solve it?
thanks in advance