Delphi DLL

Open a Persistent SMTP Connection

Demonstrates the Chilkat MailMan.OpenSmtpConnection method, which explicitly opens a connection to the SMTP server and authenticates if a username and password, OAuth2 token, or other applicable settings have been provided. This example opens the connection, notes where sending would occur, and closes it.

Background: By default, sending a single email opens a connection, sends, and closes it. When sending many messages, that per-message overhead adds up. Explicitly calling OpenSmtpConnection once, sending in a loop, then CloseSmtpConnection keeps a single authenticated session open for the whole batch — substantially faster and gentler on the server than reconnecting each time.

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Delphi DLL

var
success: Boolean;
mailman: HCkMailMan;

begin
success := False;

//  Demonstrates the MailMan.OpenSmtpConnection method, which explicitly opens a connection
//  to the SMTP server and authenticates if credentials (or an OAuth2 token) have been
//  provided.

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');

//  Explicitly open (and authenticate) the SMTP connection.

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

Memo1.Lines.Add('SMTP connection opened.');

//  ... send one or more emails here ...

//  Close the connection when done.
success := CkMailMan_CloseSmtpConnection(mailman);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

CkMailMan_Dispose(mailman);