Delphi ActiveX

Attach a File with an Explicit Content Type

Demonstrates the Chilkat Email.AddFileAttachment2 method, which attaches a file from the filesystem and lets you explicitly specify its content type rather than having Chilkat infer it from the file extension. This example attaches a binary file as application/octet-stream.

Background: Extension-based type detection is convenient but not always right — a file may have an unusual or missing extension, or you may need a very specific MIME type for the recipient to process it correctly. Specifying the content type explicitly removes the guesswork. application/octet-stream is the generic "arbitrary binary data" type, a safe default that tells the client to treat the attachment as an opaque download rather than trying to render it.

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var
success: Integer;
email: TChilkatEmail;

begin
success := 0;

//  Demonstrates the AddFileAttachment2 method, which attaches a file and lets you
//  explicitly specify its content type instead of letting Chilkat infer it.

email := TChilkatEmail.Create(Self);
email.Subject := 'Email with a file attachment';
email.Body := 'Please see the attached file.';

//  Attach a file, explicitly specifying the content type.
success := email.AddFileAttachment2('qa_data/attachments/data.bin','application/octet-stream');
if (success = 0) then
  begin
    Memo1.Lines.Add(email.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('NumAttachments = ' + IntToStr(email.NumAttachments));

//  Note: The path "qa_data/attachments/data.bin" is a relative local filesystem path,
//  relative to the current working directory of the running application.