Delphi DLL

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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Delphi DLL

var
success: Boolean;
mailman: HCkMailMan;

begin
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) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

//  Send a NOOP to keep the connection alive.
success := CkMailMan_SmtpNoop(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

success := CkMailMan_CloseSmtpConnection(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

Memo1.Lines.Add('SMTP NOOP succeeded.');

CkMailMan_Dispose(mailman);