Java

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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Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean 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 = new CkMailMan();

    //  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) {
        System.out.println(mailman.lastErrorText());
        return;
        }

    //  Send a NOOP to keep the connection alive.
    success = mailman.SmtpNoop();
    if (success == false) {
        System.out.println(mailman.lastErrorText());
        return;
        }

    success = mailman.CloseSmtpConnection();
    if (success == false) {
        System.out.println(mailman.lastErrorText());
        return;
        }

    System.out.println("SMTP NOOP succeeded.");
  }
}