Unicode C++
Send HTML Email with External CSS as Related Item

Demonstrates how to compose an HTML email with an external CSS file included as a related item and referenced by CID (Content-ID).
Chilkat Unicode C++ Downloads

Download Chilkat for Unicode C++
Unicode C++
#include <CkMailManW.h>
#include <CkEmailW.h>
#include <CkStringBuilderW.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    // The mailman object is used for sending and receiving email.
    CkMailManW mailman;

    // Use your SMTP server hostname.  This example uses office365, but it could be any SMTP server..
    mailman.put_SmtpHost(L"outlook.office365.com");
    mailman.put_SmtpPort(587);
    mailman.put_StartTLS(true);

    // Set the SMTP login/password
    mailman.put_SmtpUsername(L"OFFICE365-SMTP-LOGIN");
    mailman.put_SmtpPassword(L"OFFICE365-SMTP-PASSWORD");

    // Create a new email object
    CkEmailW email;
    email.put_Subject(L"HTML Email with embedded CSS");
    email.put_From(L"Chilkat Support <my-office365-user@mydomain.com>");
    email.AddTo(L"Chilkat Support",L"support@chilkatsoft.com");

    CkStringBuilderW sbCss;
    bool bCrlf = true;
    sbCss.AppendLine(L"body {",bCrlf);
    sbCss.AppendLine(L"    background-color: powderblue;",bCrlf);
    sbCss.AppendLine(L"}",bCrlf);
    sbCss.AppendLine(L"h1 {",bCrlf);
    sbCss.AppendLine(L"    color: blue;",bCrlf);
    sbCss.AppendLine(L"}",bCrlf);
    sbCss.AppendLine(L"p {",bCrlf);
    sbCss.AppendLine(L"    color: red;",bCrlf);
    sbCss.AppendLine(L"}",bCrlf);

    // It's possible to add a CSS file directly by calling AddRelatedFile.
    // This example will add the CSS from a string.
    const wchar_t *filenameInHtml = L"styles.css";
    const wchar_t *contentIdCss = email.addRelatedString(filenameInHtml,sbCss.getAsString(),L"utf-8");
    if (email.get_LastMethodSuccess() != true) {
        wprintf(L"%s\n",email.lastErrorText());
        return;
    }

    // The src attribute for the image tag is set to the contentIdCss:
    CkStringBuilderW sbHtml;
    sbHtml.AppendLine(L"<!DOCTYPE html>",bCrlf);
    sbHtml.AppendLine(L"<html>",bCrlf);
    sbHtml.AppendLine(L"<head>",bCrlf);
    sbHtml.AppendLine(L"  <link rel=\"stylesheet\" href=\"cid:CONTENT_ID_CSS\">",bCrlf);
    sbHtml.AppendLine(L"</head>",bCrlf);
    sbHtml.AppendLine(L"<body>",bCrlf);
    sbHtml.AppendLine(L"",bCrlf);
    sbHtml.AppendLine(L"<h1>This is a heading</h1>",bCrlf);
    sbHtml.AppendLine(L"<p>This is a paragraph.</p>",bCrlf);
    sbHtml.AppendLine(L"",bCrlf);
    sbHtml.AppendLine(L"</body>",bCrlf);
    sbHtml.AppendLine(L"</html>",bCrlf);

    int numReplacements = sbHtml.Replace(L"CONTENT_ID_CSS",contentIdCss);

    email.SetHtmlBody(sbHtml.getAsString());

    success = mailman.SendEmail(email);
    if (success != true) {
        wprintf(L"%s\n",mailman.lastErrorText());
    }
    else {
        wprintf(L"Mail Sent!\n");
    }
    }