C++

Send an SMTP NOOP Command

Demonstrates the Chilkat MailMan.SmtpNoop method, which sends an SMTP NOOP command to the server. NOOP does nothing except elicit a positive response, which is useful for keeping a connection alive or verifying it is still responsive. This example opens an SMTP connection, sends a NOOP, and closes.

Background: When holding an SMTP connection open across many sends (see OpenSmtpConnection), an idle stretch can cause the server to time out and drop the socket. A periodic NOOP keeps the session active and confirms the server is still responding, so the next SendEmail doesn't fail on a silently-closed connection.

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C++

#include <CkMailMan.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the MailMan.SmtpNoop method, which sends an SMTP NOOP command to the server.
    //  NOOP does nothing except elicit a positive response, useful for keeping a connection
    //  alive or verifying it is still responsive.

    CkMailMan mailman;

    //  Configure the SMTP server connection.
    mailman.put_SmtpHost("smtp.example.com");
    mailman.put_SmtpPort(465);
    mailman.put_SmtpSsl(true);
    mailman.put_SmtpUsername("user@example.com");
    mailman.put_SmtpPassword("myPassword");

    //  Open the SMTP connection.

    success = mailman.OpenSmtpConnection();
    if (success == false) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    //  Send a NOOP to keep the connection alive.
    success = mailman.SmtpNoop();
    if (success == false) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    success = mailman.CloseSmtpConnection();
    if (success == false) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "SMTP NOOP succeeded." << "\r\n";
    }