为什么我的发送邮件程序,第一次能正常发,连续第二次发就不能发了呢?

[airfei10]

我是想在删除按钮执行删除操作时,同时发送邮件给管理员.
我在dataview中添加了个删除摸板列,事件代码如下:
protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
HttpCookie cookie1 = Request.Cookies["user"];
string userName = cookie1.Values["userName"].ToString();
string adID = cookie1.Values["adID"].ToString();

SqlConnection con = DB.CreateDB();
con.Open();
string title = ((Label)this.GridView1.Rows[e.RowIndex].Cells[1].FindControl("lbl_title")).Text;
string input_time = ((Label)this.GridView1.Rows[e.RowIndex].Cells[4].FindControl("lbl_input_time")).Text;

SqlCommand cmd = new SqlCommand("select coursePath from courseWare where courseTitle='" + title + "'and input_time='" + input_time + "'", con);

try
{
string coursePath = Convert.ToString(cmd.ExecuteScalar());
//string Course = coursePath.Substring(coursePath.LastIndexOf("/") + 1);

cmd.CommandText = "delete from courseWare where courseTitle='" + title + "'and input_time='" + input_time + "'";
cmd.ExecuteNonQuery();

Response.Write("<script language=javascript>alert('删除课件成功！');</script>");

//发送邮件给管理员
string fromMail = "*****@126.com";
string toMail = "*****@126.com";
MailMessage mm = new MailMessage(fromMail, toMail);

mm.Subject = "彻底删除课件请求";
mm.SubjectEncoding = System.Text.Encoding.GetEncoding("gb2312");
mm.Body = "尊敬的系统管理员：" + "<br>" + "您好！" + "<br>" + "用户" + userName + "提出删除课件的请求，课件的路径及名称为：" + coursePath + ",收到此请求后请进行服务器相应课件的清理．" + "<br>" + "请重新登录来验证您操作的正确性，如果还有问题应及时与系统管理员联系，谢谢您的支持和使用！" + "<br>" + "系统管理员的E-mail：[e-mail]";
mm.IsBodyHtml = true;
mm.BodyEncoding = System.Text.Encoding.GetEncoding("gb2312");

SmtpClient sc = new SmtpClient();

try
{
sc.Send(mm);
}
catch (Exception ex)
{
if (ex is SmtpException)
{
Response.Write("<script language=javascript>alert('删除课件请求邮件发送失败，请及时与管理员联系！');</script>");
}
else
{
Response.Write(e.ToString());
}
}
}
catch (Exception ex)
{
Response.Write("<script language=javascript>alert('删除课件失败，有疑问请联系管理员！');</script>");
}
finally
{
con.Close();
}
}

麻烦大家给我支支招,谢谢

[wlql]

我用java写的程序也遇到同样的问题。可能和验证有关系