How to send only one quiz from the database to all users?

protected void Page_Load(object sender, EventArgs e)
    {
        SendEmailTOAllUser();
    }


    protected void SendEmail(string toAddresses, string fromAddress, string MailSubject, string MessageBody, bool isBodyHtml)
    {
        SmtpClient sc = new SmtpClient("SMTP (MAIL) ADDREASS");
        try
        {
            MailMessage msg = new MailMessage();
            msg.From = new MailAddress("pssp@gmail.com", "Our System");

            // In case the mail system doesn't like no to recipients. This could be removed
            msg.To.Add("psTest@gmail.com");

            msg.Bcc.Add(toAddresses);
            msg.Subject = MailSubject;
            msg.Body = MessageBody;
            msg.IsBodyHtml = isBodyHtml;

            sc.Send(msg);
        }
        catch (Exception ex)
        {
            throw ex;
        }

    }


    protected void SendEmailTOAllUser()
    {
        string connString = "Data Source=localhost\\sqlexpress;Initial Catalog=spTest;Integrated Security=True";

        using (SqlConnection conn = new SqlConnection(connString))
        {
            var sbEmailAddresses = new System.Text.StringBuilder(1000);
            var quizIds = new List();

            // Open DB connection.
            conn.Open();

            string cmdText = "SELECT QuizID FROM dbo.QUIZ WHERE IsSent <> 1";
            using (SqlCommand cmd = new SqlCommand(cmdText, conn))
            {
                SqlDataReader reader = cmd.ExecuteReader();
                if (reader != null)
                {
                    while (reader.Read())
                    {
                        // There is only 1 column, so just retrieve it using the ordinal position
                        quizIds.Add(reader.GetInt32(0));
                    }
                }
                reader.Close();
            }

            string cmdText2 = "SELECT Username FROM dbo.employee";
            Collection emailAddresses = new Collection();
            using (SqlCommand cmd = new SqlCommand(cmdText2, conn))
            {
                SqlDataReader reader = cmd.ExecuteReader();
                if (reader != null)
                {
                    while (reader.Read())
                    {
                        string emailTo = reader["Username"].ToString();
                        string receiverEmail = emailTo + "@gmail.com";
                        emailAddresses.Add(receiverEmail);
                    }
                }
                reader.Close();
            }

            string cmdText3 = "UPDATE dbo.Quiz SET IsSent = 1 WHERE QuizId = @QuizID";
            using (SqlCommand cmd = new SqlCommand(cmdText3, conn))
            {
                // Add the parameter to the command
                var oParameter = cmd.Parameters.Add("@QuizID", SqlDbType.Int);
                // Get a local copy of the email addresses
                var sEMailAddresses = sbEmailAddresses.ToString();

                foreach (int quizid in quizIds)
                {
                    string link = " Click here to participate ";
                    string body = @" Please try to participate "
                                        + link +
                                        @" 
                    This email was generated using the Safety Portal . 
                    Please do not reply to this email.
                    ";

                    foreach (string email in emailAddresses)
                    {
                        SendEmail(email, "", "Notification Email Subject", body, true);
                    }
                    // Update the parameter for the current quiz
                    oParameter.Value = quizid;
                    // And execute the command
                    cmd.ExecuteNonQuery();
                }
            }
            conn.Close();
        }

    }