Search in data grids problem

public void FilterFromSubject(string mailSubject)
      {
          List<unreademails> list = (List<unreademails>)dgvUnreadMails.DataSource;
          //List<string> myUnreadMailList;
          try
          {
              List<unreademails> filteredList = (List<unreademails>)(from ci in list
                                                                     where ci.Subject.ToLower().Contains(mailSubject)

                                                                     select ci).ToList<unreademails>();
              dgvUnreadMails.DataSource = filteredList;
              btnCancel.Enabled = true;
          }
          catch (System.Exception)
          {

              MessageBox.Show("Import E-mails first", "Empty Table", MessageBoxButtons.OK, MessageBoxIcon.Information);
              btnSave.Enabled = false;
          }
      }</unreademails></unreademails></unreademails></string></unreademails></unreademails>

private object GetDynamicDataTable(List<unreademails> emailList, List<string> words)
      {
          DataTable dtList = new DataTable();
          dtList.Columns.Add("Sender Name");
          dtList.Columns.Add("Sender Address");
          dtList.Columns.Add("Date Time");
          dtList.Columns.Add("Subject");
          dtList.Columns.Add("Body Content");
          dtList.Columns.Add("Attachments");
          dtList.Columns.Add("EntryID");

          foreach (string dynamic in words)
          {
              dtList.Columns.Add(dynamic);
              cmbWords.Items.Add(dynamic);
          }

          foreach (UnreadEmails mail in emailList)
          {
              DataRow dr = dtList.NewRow();
              dr["Sender Name"] = mail.SenderName;
              dr["Sender Address"] = mail.SenderAddress;
              dr["Date Time"] = mail.RecivedTime;
              dr["Body Content"] = mail.BodyContent;
              dr["Subject"] = mail.Subject;
              dr["EntryID"] = mail.EntryID;
              foreach (string item in words)
              {
                  object count = GetWordCount(mail.BodyContent.ToString(), item);
                  dr[item] = count;
              }

              dtList.Rows.Add(dr);
          }
          return dtList;
      }</string></unreademails>