Send an SMTP NOOP Command

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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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#include <C_CkMailMan.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkMailMan mailman;

    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.

    mailman = CkMailMan_Create();

    //  Configure the SMTP server connection.
    CkMailMan_putSmtpHost(mailman,"smtp.example.com");
    CkMailMan_putSmtpPort(mailman,465);
    CkMailMan_putSmtpSsl(mailman,TRUE);
    CkMailMan_putSmtpUsername(mailman,"user@example.com");
    CkMailMan_putSmtpPassword(mailman,"myPassword");

    //  Open the SMTP connection.

    success = CkMailMan_OpenSmtpConnection(mailman);
    if (success == FALSE) {
        printf("%s\n",CkMailMan_lastErrorText(mailman));
        CkMailMan_Dispose(mailman);
        return;
    }

    //  Send a NOOP to keep the connection alive.
    success = CkMailMan_SmtpNoop(mailman);
    if (success == FALSE) {
        printf("%s\n",CkMailMan_lastErrorText(mailman));
        CkMailMan_Dispose(mailman);
        return;
    }

    success = CkMailMan_CloseSmtpConnection(mailman);
    if (success == FALSE) {
        printf("%s\n",CkMailMan_lastErrorText(mailman));
        CkMailMan_Dispose(mailman);
        return;
    }

    printf("SMTP NOOP succeeded.\n");


    CkMailMan_Dispose(mailman);

    }