Send email to recepient email address stored in database in ASP.Net

This is the sample project which i have created and the below is the aspx code

 <form id="form1" runat="server">
    <div>
        <asp:DropDownList ID='ddlEmployeeId' runat="server">
        </asp:DropDownList>
        <asp:Button ID="btnSendEmail" runat="server" Text="Send Email" OnClick="OnSendEmailClicked" />
    </div>
    </form>

protected void Page_Load(object sender, EventArgs e)
        {
            ddlEmployeeId.DataSource = GetData("SELECT ecode,empname FROM Leaves");
            ddlEmployeeId.DataTextField = "empname";
            ddlEmployeeId.DataValueField = "ecode";
            ddlEmployeeId.DataBind();
        }

        protected void OnSendEmailClicked(object sender, EventArgs e)
        {
            DataTable dataTable = new DataTable();
            dataTable = GetData("SELECT ecode,empname,Department,pl,sl,lop,totdays,depthead FROM Leaves WHERE ecode='" + ddlEmployeeId.SelectedItem.Value + "'");
            string recepientEmail = dataTable.Rows[0]["depthead"].ToString();
            string body = "<br /><br />Leave Application<br /> EmpCode: " + dataTable.Rows[0]["ecode"].ToString() + "<br /> Employee Name: " + dataTable.Rows[0]["empName"].ToString() + "<br />Department: " + dataTable.Rows[0]["Department"].ToString() + "<br />PL: " + dataTable.Rows[0]["pl"].ToString() + "<br />SL: " + dataTable.Rows[0]["sl"].ToString() + "<br />LOP: " + dataTable.Rows[0]["lop"].ToString() + "<br />Total Days: " + dataTable.Rows[0]["totdays"].ToString() + "";
            string subject = "Leave Application";
            SendEmail(recepientEmail, subject, body);
        }

        private DataTable GetData(string query)
        {
            string connectionString = ConfigurationManager.ConnectionStrings["MyCon"].ConnectionString;
            DataTable dataTable = new DataTable();
            SqlConnection sqlconnection = new SqlConnection();
            sqlconnection.ConnectionString = connectionString;
            sqlconnection.Open();
            SqlCommand sqlCommand = new SqlCommand(query, sqlconnection);
            SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
            dataTable.Load(sqlDataReader);
            sqlconnection.Close();
            return dataTable;
        }


        public static void SendEmail(string recepientEmail, string subject, string body)
        {
            using (MailMessage mm = new MailMessage())
            {
                string fromEmailAddress = "Youremail@gmail.com";
                mm.From = new MailAddress(fromEmailAddress);
                mm.To.Add(new MailAddress(recepientEmail));
                mm.Subject = subject;
                mm.Body = body;
                mm.IsBodyHtml = true;
                SmtpClient smtp = new SmtpClient();
                smtp.Host = "smtp.gmail.com";
                smtp.EnableSsl = true;
                System.Net.NetworkCredential networkCred = new System.Net.NetworkCredential();
                networkCred.UserName = fromEmailAddress;
                networkCred.Password = "your gmail password";
                smtp.UseDefaultCredentials = true;
                smtp.Credentials = networkCred;
                smtp.Port = 587;
                smtp.Send(mm);
            }
        }

You will also have to use this NameSpace

using System.Net.Mail;

and check whether it works