1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23/* <DESC>
24 * SMTP example showing how to send e-mails
25 * </DESC>
26 */
27
28#include <stdio.h>
29#include <string.h>
30#include <curl/curl.h>
31
32/* This is a simple example showing how to send mail using libcurl's SMTP
33 * capabilities. For an example of using the multi interface please see
34 * smtp-multi.c.
35 *
36 * Note that this example requires libcurl 7.20.0 or above.
37 */
38
39#define FROM    "<sender@example.org>"
40#define TO      "<addressee@example.net>"
41#define CC      "<info@example.org>"
42
43static const char *payload_text[] = {
44  "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n",
45  "To: " TO "\r\n",
46  "From: " FROM "(Example User)\r\n",
47  "Cc: " CC "(Another example User)\r\n",
48  "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
49  "rfcpedant.example.org>\r\n",
50  "Subject: SMTP example message\r\n",
51  "\r\n", /* empty line to divide headers from body, see RFC5322 */
52  "The body of the message starts here.\r\n",
53  "\r\n",
54  "It could be a lot of lines, could be MIME encoded, whatever.\r\n",
55  "Check RFC5322.\r\n",
56  NULL
57};
58
59struct upload_status {
60  int lines_read;
61};
62
63static size_t payload_source(void *ptr, size_t size, size_t nmemb, void *userp)
64{
65  struct upload_status *upload_ctx = (struct upload_status *)userp;
66  const char *data;
67
68  if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
69    return 0;
70  }
71
72  data = payload_text[upload_ctx->lines_read];
73
74  if(data) {
75    size_t len = strlen(data);
76    memcpy(ptr, data, len);
77    upload_ctx->lines_read++;
78
79    return len;
80  }
81
82  return 0;
83}
84
85int main(void)
86{
87  CURL *curl;
88  CURLcode res = CURLE_OK;
89  struct curl_slist *recipients = NULL;
90  struct upload_status upload_ctx;
91
92  upload_ctx.lines_read = 0;
93
94  curl = curl_easy_init();
95  if(curl) {
96    /* This is the URL for your mailserver */
97    curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");
98
99    /* Note that this option isn't strictly required, omitting it will result
100     * in libcurl sending the MAIL FROM command with empty sender data. All
101     * autoresponses should have an empty reverse-path, and should be directed
102     * to the address in the reverse-path which triggered them. Otherwise,
103     * they could cause an endless loop. See RFC 5321 Section 4.5.5 for more
104     * details.
105     */
106    curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
107
108    /* Add two recipients, in this particular case they correspond to the
109     * To: and Cc: addressees in the header, but they could be any kind of
110     * recipient. */
111    recipients = curl_slist_append(recipients, TO);
112    recipients = curl_slist_append(recipients, CC);
113    curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
114
115    /* We're using a callback function to specify the payload (the headers and
116     * body of the message). You could just use the CURLOPT_READDATA option to
117     * specify a FILE pointer to read from. */
118    curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
119    curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
120    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
121
122    /* Send the message */
123    res = curl_easy_perform(curl);
124
125    /* Check for errors */
126    if(res != CURLE_OK)
127      fprintf(stderr, "curl_easy_perform() failed: %s\n",
128              curl_easy_strerror(res));
129
130    /* Free the list of recipients */
131    curl_slist_free_all(recipients);
132
133    /* curl won't send the QUIT command until you call cleanup, so you should
134     * be able to re-use this connection for additional messages (setting
135     * CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT as required, and calling
136     * curl_easy_perform() again. It may not be a good idea to keep the
137     * connection open for a very long time though (more than a few minutes
138     * may result in the server timing out the connection), and you do want to
139     * clean up in the end.
140     */
141    curl_easy_cleanup(curl);
142  }
143
144  return (int)res;
145}
146