I need to develop a mailing system in the intranet web-based application that I am working on it for my company. I am developing it with ASP.NET and C#. The purpose of this system is to let the admin to be able to send emails to the users. I developed this system and I tested for 25 users and it works fine.
Now, I have 386 users in the database, so when I tried to send them emails, I got the following error:
> Exception Details: System.Net.Mail.SmtpException: The operation has
> timed out.
I think this is because of ISP in my company blocked sending email to many users after a certain number of milliseconds. I tried to use SendAsync but I found it will not benefit me.
Also, I tried to maximize the execution timeout in the Web.config file as folloiwng:
<location path="Email4.aspx">
<system.web>
<httpRuntime executionTimeout="180"/>
</system.web>
</location>but I failed. **So how to fix this problem?**
My Code-Behind (C#):
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("MAIL.companyDomainName.com");
try
{
MailMessage msg = new MailMessage();
msg.From = new MailAddress("pssp@companyDomainName.com", "PMOD Safety Services Portal (PSSP)");
// In case the mail system doesn't like no to recipients. This could be removed
//msg.To.Add("pssp@companyDomainName.com");
msg.Bcc.Add(toAddresses);
msg.Subject = MailSubject;
msg.Body = MessageBody;
msg.IsBodyHtml = isBodyHtml;
//Response.Write(msg);
sc.Send(msg);
}
catch (Exception ex)
{
throw ex;
}
}
protected void SendEmailTOAllUser()
{
string connString = "Data Source=localhost\\sqlexpress;Initial Catalog=psspEmail;Integrated Security=True";
using (SqlConnection conn = new SqlConnection(connString))
{
var sbEmailAddresses = new System.Text.StringBuilder(1000);
string quizid = "";
// Open DB connection.
conn.Open();
string cmdText = "SELECT MIN (QuizID) As mQuizID 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
quizid = reader["mQuizID"].ToString();
}
}
reader.Close();
}
string cmdText2 = "SELECT Username FROM dbo.employee";
using (SqlCommand cmd = new SqlCommand(cmdText2, conn))
{
SqlDataReader reader = cmd.ExecuteReader();
if (reader != null)
{
while (reader.Read())
{
var sName = reader.GetString(0);
if (!string.IsNullOrEmpty(sName))
{
if (sbEmailAddresses.Length != 0)
{
sbEmailAddresses.Append(",");
}
// Just use the ordinal position for the user name since there is only 1 column
sbEmailAddresses.Append(sName).Append("@companyDomainName.com");
}
}
}
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();
string link = "<a href='http://pmv/pssp/StartQuiz.aspx?testid=" + quizid + "'> Click here to participate </a>";
string body = @"Good day, <br /><br />
<b> Please participate in the new short safety quiz </b>"
+ link +
@"<br /><br />
Also, give yourself a chance to gain more safety culture by reading the PMOD Newsletter.
<br /> <br /><br /> <br />
This email was generated using the <a href='http://pmv/pssp/Default.aspx'>PMOD Safety Services Portal (PSSP) </a>.
Please do not reply to this email.
";
SendEmail(sEMailAddresses, "", "Notification of New Weekly Safety Quiz", body, true);
// Update the parameter for the current quiz
oParameter.Value = quizid;
// And execute the command
cmd.ExecuteNonQuery();
}
conn.Close();
}
}