Unicode C
Force Quoted-Printable Encoding for Email

Demonstrates how to force the quoted-printable encoding for email.
Chilkat Unicode C Downloads

Unicode C
#include <C_CkEmailW.h>
#include <C_CkMailManW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkEmailW email;
    HCkMailManW mailman;

    success = FALSE;

    email = CkEmailW_Create();

    CkEmailW_putSubject(email,L"test");
    CkEmailW_putFrom(email,L"bob@example.com");
    CkEmailW_AddTo(email,L"Mary",L"mary@example.com");

    //  Add plain-text and HTML alternative bodies.
    //  Include some "=" chars so we can see the quoted-printable encoding when used..
    CkEmailW_AddPlainTextAlternativeBody(email,L"This is a test == Hello World!");
    CkEmailW_AddHtmlAlternativeBody(email,L"<html><body>This is a test == Hello World!</body></html>");

    //  Examine the MIME of the email to see that it does not use quoted-printable.
    //  (If the email contained non-usascii chars, it would automatically use quoted-printable.)
    mailman = CkMailManW_Create();
    wprintf(L"%s\n",CkMailManW_renderToMime(mailman,email));

    //  Here is the MIME before forcing quoted-printable.
    //  Notice the Content-Transfer-Encoding is "7bit" (not "quoted-printable")

    //  MIME-Version: 1.0
    //  Date: Tue, 29 Sep 2020 12:26:52 -0500
    //  Message-ID: <CF274FC0A2F82B98A05B7507DF7DFB966A2C0EB8@CHILKATSLICE>
    //  Content-Type: multipart/alternative;
    //   boundary="------------080901080902080000030208"
    //  X-Priority: 3 (Normal)
    //  Subject: test
    //  From: bob@example.com
    //  To: Mary <mary@example.com>
    //  
    //  --------------080901080902080000030208
    //  Content-Transfer-Encoding: 7bit
    //  Content-Type: text/plain; charset=us-ascii; format=flowed
    //  
    //  This is a test == Hello World!
    //  --------------080901080902080000030208
    //  Content-Transfer-Encoding: 7bit
    //  Content-Type: text/html; charset=us-ascii
    //  
    //  <html><body>This is a test == Hello World!</body></html>
    //  --------------080901080902080000030208--

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

    //  To force quoted-printable, set the Content-Transfer-Encoding header.
    //  It will automatically propagate as needed to the MIME sub-parts.
    CkEmailW_AddHeaderField(email,L"Content-Transfer-Encoding",L"quoted-printable");
    wprintf(L"%s\n",CkMailManW_renderToMime(mailman,email));

    //  MIME-Version: 1.0
    //  Date: Tue, 29 Sep 2020 12:26:52 -0500
    //  Message-ID: <F36B276E3A720FE5111D15CE9142C8909E1F5AB9@CHILKATSLICE>
    //  Content-Type: multipart/alternative;
    //   boundary="------------080901080902080000030208"
    //  X-Priority: 3 (Normal)
    //  Subject: test
    //  From: bob@example.com
    //  To: Mary <mary@example.com>
    //  
    //  --------------080901080902080000030208
    //  Content-Transfer-Encoding: quoted-printable
    //  Content-Type: text/plain; charset=us-ascii; format=flowed
    //  
    //  This is a test =3D=3D Hello World!
    //  --------------080901080902080000030208
    //  Content-Transfer-Encoding: quoted-printable
    //  Content-Type: text/html; charset=us-ascii
    //  
    //  <html><body>This is a test =3D=3D Hello World!</body></html>
    //  --------------080901080902080000030208--


    CkEmailW_Dispose(email);
    CkMailManW_Dispose(mailman);

    }