C#

Add Header Field to MIME Sub-Header in Email

See more Email Object Examples

Demonstrates how to add a header field to one of the attachment sub-headers in an email. C#

bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

Chilkat.Email email = new Chilkat.Email();

email.Subject = "test";
email.AddTo("Chilkat","support@chilkatsoft.com");
email.From = "Matt <matt@example.com>";
email.Body = "This is a simple plain-text body.";

success = email.AddFileAttachment2("qa_data/1.HPM","application/x-hprimnet");
if (success == false) {
    Debug.WriteLine(email.LastErrorText);
    return;
}

//  Add a "ContentDescription: HPM/3.0" in the attachment's sub-header.
//  The 1st attachment is at index 0.
email.AddAttachmentHeader(0,"Content-Description","HPM/3.0");

//  Show the email MIME:
Debug.WriteLine(email.GetMime());

//  This is the output:

//  MIME-Version: 1.0
//  Date: Wed, 16 Jan 2019 10:05:18 -0600
//  Message-ID: <93B88835586270B7BE5202F84E171F29C10BA935@CHILKATSLICE>
//  Content-Type: multipart/mixed; boundary="------------000502000000020502010608"
//  X-Priority: 3 (Normal)
//  Subject: test
//  To: Chilkat <support@chilkatsoft.com>
//  From: Matt <matt@example.com>
//  
//  --------------000502000000020502010608
//  Content-Type: text/plain; charset=us-ascii; format=flowed
//  Content-Transfer-Encoding: 7bit
//  
//  This is a simple plain-text body.
//  --------------000502000000020502010608
//  Content-Type: application/x-hprimnet; name="1.HPM"
//  Content-Transfer-Encoding: base64
//  Content-Disposition: attachment; filename="1.HPM"
//  Content-Description: HPM/3.0
//  
//  FILE_DATA_IS_HERE...
//  
//  --------------000502000000020502010608--