1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25 /* <DESC>
26 * Send SMTP mime emails
27 * </DESC>
28 */
29
30 #include <stdio.h>
31 #include <string.h>
32 #include <curl/curl.h>
33
34 /* This is a simple example showing how to send mime mail using libcurl's SMTP
35 * capabilities. For an example of using the multi interface please see
36 * smtp-multi.c.
37 *
38 * Note that this example requires libcurl 7.56.0 or above.
39 */
40
41 #define FROM "<sender@example.org>"
42 #define TO "<addressee@example.net>"
43 #define CC "<info@example.org>"
44
45 static const char *headers_text[] = {
46 "Date: Tue, 22 Aug 2017 14:08:43 +0100",
47 "To: " TO,
48 "From: " FROM " (Example User)",
49 "Cc: " CC " (Another example User)",
50 "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
51 "rfcpedant.example.org>",
52 "Subject: example sending a MIME-formatted message",
53 NULL
54 };
55
56 static const char inline_text[] =
57 "This is the inline text message of the email.\r\n"
58 "\r\n"
59 " It could be a lot of lines that would be displayed in an email\r\n"
60 "viewer that is not able to handle HTML.\r\n";
61
62 static const char inline_html[] =
63 "<html><body>\r\n"
64 "<p>This is the inline <b>HTML</b> message of the email.</p>"
65 "<br />\r\n"
66 "<p>It could be a lot of HTML data that would be displayed by "
67 "email viewers able to handle HTML.</p>"
68 "</body></html>\r\n";
69
70
main(void)71 int main(void)
72 {
73 CURL *curl;
74 CURLcode res = CURLE_OK;
75
76 curl = curl_easy_init();
77 if(curl) {
78 struct curl_slist *headers = NULL;
79 struct curl_slist *recipients = NULL;
80 struct curl_slist *slist = NULL;
81 curl_mime *mime;
82 curl_mime *alt;
83 curl_mimepart *part;
84 const char **cpp;
85
86 /* This is the URL for your mailserver */
87 curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");
88
89 /* Note that this option is not strictly required, omitting it results in
90 * libcurl sending the MAIL FROM command with empty sender data. All
91 * autoresponses should have an empty reverse-path, and should be directed
92 * to the address in the reverse-path which triggered them. Otherwise,
93 * they could cause an endless loop. See RFC 5321 Section 4.5.5 for more
94 * details.
95 */
96 curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
97
98 /* Add two recipients, in this particular case they correspond to the
99 * To: and Cc: addressees in the header, but they could be any kind of
100 * recipient. */
101 recipients = curl_slist_append(recipients, TO);
102 recipients = curl_slist_append(recipients, CC);
103 curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
104
105 /* allow one of the recipients to fail and still consider it okay */
106 curl_easy_setopt(curl, CURLOPT_MAIL_RCPT_ALLOWFAILS, 1L);
107
108 /* Build and set the message header list. */
109 for(cpp = headers_text; *cpp; cpp++)
110 headers = curl_slist_append(headers, *cpp);
111 curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
112
113 /* Build the mime message. */
114 mime = curl_mime_init(curl);
115
116 /* The inline part is an alternative proposing the html and the text
117 versions of the email. */
118 alt = curl_mime_init(curl);
119
120 /* HTML message. */
121 part = curl_mime_addpart(alt);
122 curl_mime_data(part, inline_html, CURL_ZERO_TERMINATED);
123 curl_mime_type(part, "text/html");
124
125 /* Text message. */
126 part = curl_mime_addpart(alt);
127 curl_mime_data(part, inline_text, CURL_ZERO_TERMINATED);
128
129 /* Create the inline part. */
130 part = curl_mime_addpart(mime);
131 curl_mime_subparts(part, alt);
132 curl_mime_type(part, "multipart/alternative");
133 slist = curl_slist_append(NULL, "Content-Disposition: inline");
134 curl_mime_headers(part, slist, 1);
135
136 /* Add the current source program as an attachment. */
137 part = curl_mime_addpart(mime);
138 curl_mime_filedata(part, "smtp-mime.c");
139 curl_easy_setopt(curl, CURLOPT_MIMEPOST, mime);
140
141 /* Send the message */
142 res = curl_easy_perform(curl);
143
144 /* Check for errors */
145 if(res != CURLE_OK)
146 fprintf(stderr, "curl_easy_perform() failed: %s\n",
147 curl_easy_strerror(res));
148
149 /* Free lists. */
150 curl_slist_free_all(recipients);
151 curl_slist_free_all(headers);
152
153 /* curl does not send the QUIT command until you call cleanup, so you
154 * should be able to reuse this connection for additional messages
155 * (setting CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT as required, and
156 * calling curl_easy_perform() again. It may not be a good idea to keep
157 * the connection open for a long time though (more than a few minutes may
158 * result in the server timing out the connection), and you do want to
159 * clean up in the end.
160 */
161 curl_easy_cleanup(curl);
162
163 /* Free multipart message. */
164 curl_mime_free(mime);
165 }
166
167 return (int)res;
168 }
169