(.NET Core C#) Send Email to Distribution List

Sends the same email to a list of 1000 email addresses in 50 sends where each email has 20 recipients.

Note: Chilkat is not intended nor designed for mass emailing. A solution such as this might be used for a corporate emailing to employees, or an emailing to newsletter subscribers.

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// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.MailMan mailman = new Chilkat.MailMan();
bool success;

mailman.SmtpHost = "smtp.mymailserver.com";
mailman.SmtpPort = 465;
mailman.SmtpSsl = true;
mailman.SmtpUsername = "myUsername";
mailman.SmtpPassword = "myPassword";

// Create a new email object
Chilkat.Email email = new Chilkat.Email();
email.Subject = "This is a test";
email.Body = "This is a test";
email.From = "Senders Name <sender@example.com>";
email.AddTo("Subscribers","subscribers@example.com");

Chilkat.BinData bdMime = new Chilkat.BinData();
mailman.RenderToMimeBd(email,bdMime);

// Load a file containing one email address per line.
Chilkat.StringTable distList = new Chilkat.StringTable();
success = distList.AppendFromFile(1000,"utf-8","qa_data/distList.txt");
if (success == false) {
    Debug.WriteLine(distList.LastErrorText);
    return;
}

Chilkat.StringBuilder sbRecipients = new Chilkat.StringBuilder();

int i = 0;
int szDistList = distList.Count;
int j = 0;
while (i < szDistList) {

    // Build a list of comma-separated recipients.
    if (j > 0) {
        sbRecipients.Append(",");
    }

    sbRecipients.Append(distList.StringAt(i));

    i = i + 1;
    j = j + 1;

    // If we have 20 recipients, or we have the final recipient in the final chunk, then send.
    if ((j == 20) || (i == szDistList)) {
        success = mailman.SendMimeBd("sender@example.com",sbRecipients.GetAsString(),bdMime);
        if (success != true) {
            Debug.WriteLine(mailman.LastErrorText);
            return;
        }

        j = 0;
        sbRecipients.Clear();
    }

}

success = mailman.CloseSmtpConnection();
if (success != true) {
    Debug.WriteLine("Connection to SMTP server not closed cleanly.");
}

Debug.WriteLine("Email sent to distirbution list.");