text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
   *
   * This software is licensed as described in the file COPYING, which
   * you should have received as part of this distribution. The terms
   * are also available at https://curl.haxx.se/docs/copyright.html.
   *
   * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   * copies of the Software, and permit persons to whom the Software is
   * furnished to do so, under the terms of the COPYING file.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ***************************************************************************/
  
  /* <DESC>
   * SMTP example showing how to send mime e-mails
   * </DESC>
   */
  
  #include <stdio.h>
  #include <string.h>
  #include <curl/curl.h>
  
  /* This is a simple example showing how to send mime mail using libcurl's SMTP
   * capabilities. For an example of using the multi interface please see
   * smtp-multi.c.
   *
   * Note that this example requires libcurl 7.56.0 or above.
   */
  
  #define FROM    "<sender@example.org>"
  #define TO      "<addressee@example.net>"
  #define CC      "<info@example.org>"
  
  static const char *headers_text[] = {
    "Date: Tue, 22 Aug 2017 14:08:43 +0100",
    "To: " TO,
    "From: " FROM " (Example User)",
    "Cc: " CC " (Another example User)",
    "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
      "rfcpedant.example.org>",
    "Subject: example sending a MIME-formatted message",
    NULL
  };
  
  static const char inline_text[] =
    "This is the inline text message of the e-mail.\r\n"
    "\r\n"
    "  It could be a lot of lines that would be displayed in an e-mail\r\n"
    "viewer that is not able to handle HTML.\r\n";
  
  static const char inline_html[] =
    "<html><body>\r\n"
    "<p>This is the inline <b>HTML</b> message of the e-mail.</p>"
    "<br />\r\n"
    "<p>It could be a lot of HTML data that would be displayed by "
    "e-mail viewers able to handle HTML.</p>"
    "</body></html>\r\n";
  
  
  int main(void)
  {
    CURL *curl;
    CURLcode res = CURLE_OK;
    struct curl_slist *headers = NULL;
    struct curl_slist *recipients = NULL;
    struct curl_slist *slist = NULL;
    curl_mime *mime;
    curl_mime *alt;
    curl_mimepart *part;
    const char **cpp;
  
    curl = curl_easy_init();
    if(curl) {
      /* This is the URL for your mailserver */
      curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");
  
      /* Note that this option isn't strictly required, omitting it will result
       * in libcurl sending the MAIL FROM command with empty sender data. All
       * autoresponses should have an empty reverse-path, and should be directed
       * to the address in the reverse-path which triggered them. Otherwise,
       * they could cause an endless loop. See RFC 5321 Section 4.5.5 for more
       * details.
       */
      curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
  
      /* Add two recipients, in this particular case they correspond to the
       * To: and Cc: addressees in the header, but they could be any kind of
       * recipient. */
      recipients = curl_slist_append(recipients, TO);
      recipients = curl_slist_append(recipients, CC);
      curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
  
      /* Build and set the message header list. */
      for(cpp = headers_text; *cpp; cpp++)
        headers = curl_slist_append(headers, *cpp);
      curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
  
      /* Build the mime message. */
      mime = curl_mime_init(curl);
  
      /* The inline part is an alternative proposing the html and the text
         versions of the e-mail. */
      alt = curl_mime_init(curl);
  
      /* HTML message. */
      part = curl_mime_addpart(alt);
      curl_mime_data(part, inline_html, CURL_ZERO_TERMINATED);
      curl_mime_type(part, "text/html");
  
      /* Text message. */
      part = curl_mime_addpart(alt);
      curl_mime_data(part, inline_text, CURL_ZERO_TERMINATED);
  
      /* Create the inline part. */
      part = curl_mime_addpart(mime);
      curl_mime_subparts(part, alt);
      curl_mime_type(part, "multipart/alternative");
      slist = curl_slist_append(NULL, "Content-Disposition: inline");
      curl_mime_headers(part, slist, 1);
  
      /* Add the current source program as an attachment. */
      part = curl_mime_addpart(mime);
      curl_mime_filedata(part, "smtp-mime.c");
      curl_easy_setopt(curl, CURLOPT_MIMEPOST, mime);
  
      /* Send the message */
      res = curl_easy_perform(curl);
  
      /* Check for errors */
      if(res != CURLE_OK)
        fprintf(stderr, "curl_easy_perform() failed: %s\n",
                curl_easy_strerror(res));
  
      /* Free lists. */
      curl_slist_free_all(recipients);
      curl_slist_free_all(headers);
  
      /* curl won't send the QUIT command until you call cleanup, so you should
       * be able to re-use this connection for additional messages (setting
       * CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT as required, and calling
       * curl_easy_perform() again. It may not be a good idea to keep the
       * connection open for a very long time though (more than a few minutes
       * may result in the server timing out the connection), and you do want to
       * clean up in the end.
       */
      curl_easy_cleanup(curl);
  
      /* Free multipart message. */
      curl_mime_free(mime);
    }
  
    return (int)res;
  }
  