Sample code for 30+ languages & platforms
Unicode C++

Auto-Generate or Explicitly Specify the Message-ID Email Header

Demonstrates how to auto-generate or explicitly specify the Message-ID header field.

Chilkat Unicode C++ Downloads

Unicode C++
#include <CkEmailW.h>
#include <CkMailManW.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkEmailW email;

    email.put_Subject(L"test");
    email.put_Body(L"test");
    email.AddTo(L"Joe",L"joe@example1.com");
    email.put_From(L"mary@example2.com");

    CkMailManW mailman;

    //  When the mailman sends email, it renders the email to be sent,
    //  and then sends the rendered MIME.

    //  Instead of actually sending the email, this example will render
    //  to MIME so we can see what would be sent..

    //  We can explicitly set the Message-ID like this:
    mailman.put_AutoGenMessageId(false);
    email.AddHeaderField(L"Message-ID",L"<xyz123@abc>");

    const wchar_t *mimeStr = mailman.renderToMime(email);
    wprintf(L"%s\n",mimeStr);

    //  This is what we get:

    //  MIME-Version: 1.0
    //  Date: Mon, 20 Jul 2020 17:20:09 -0500
    //  Message-ID: <xyz123@abc>
    //  Content-Type: text/plain; charset=us-ascii; format=flowed
    //  Content-Transfer-Encoding: 7bit
    //  X-Priority: 3 (Normal)
    //  Subject: test
    //  To: Joe <joe@example1.com>
    //  From: mary@example2.com
    //  
    //  test

    wprintf(L"--------\n");

    //  If we auto-generate...
    mailman.put_AutoGenMessageId(true);
    mimeStr = mailman.renderToMime(email);
    wprintf(L"%s\n",mimeStr);

    //  We get this:

    //  MIME-Version: 1.0
    //  Date: Mon, 20 Jul 2020 17:21:20 -0500
    //  Message-ID: <04EDE096BBFE484967F6398A973B0FCF6EA09A44@CHILKATSLICE>
    //  Content-Type: text/plain; charset=us-ascii; format=flowed
    //  Content-Transfer-Encoding: 7bit
    //  X-Priority: 3 (Normal)
    //  Subject: test
    //  To: Joe <joe@example1.com>
    //  From: mary@example2.com
    //  
    //  test
    }