1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2019, 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 mime 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 mime 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 7.56.0 or above.
37  */
38 
39 #define FROM    "<sender@example.org>"
40 #define TO      "<addressee@example.net>"
41 #define CC      "<info@example.org>"
42 
43 static const char *headers_text[] = {
44   "Date: Tue, 22 Aug 2017 14:08:43 +0100",
45   "To: " TO,
46   "From: " FROM " (Example User)",
47   "Cc: " CC " (Another example User)",
48   "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
49     "rfcpedant.example.org>",
50   "Subject: example sending a MIME-formatted message",
51   NULL
52 };
53 
54 static const char inline_text[] =
55   "This is the inline text message of the e-mail.\r\n"
56   "\r\n"
57   "  It could be a lot of lines that would be displayed in an e-mail\r\n"
58   "viewer that is not able to handle HTML.\r\n";
59 
60 static const char inline_html[] =
61   "<html><body>\r\n"
62   "<p>This is the inline <b>HTML</b> message of the e-mail.</p>"
63   "<br />\r\n"
64   "<p>It could be a lot of HTML data that would be displayed by "
65   "e-mail viewers able to handle HTML.</p>"
66   "</body></html>\r\n";
67 
68 
main(void)69 int main(void)
70 {
71   CURL *curl;
72   CURLcode res = CURLE_OK;
73 
74   curl = curl_easy_init();
75   if(curl) {
76     struct curl_slist *headers = NULL;
77     struct curl_slist *recipients = NULL;
78     struct curl_slist *slist = NULL;
79     curl_mime *mime;
80     curl_mime *alt;
81     curl_mimepart *part;
82     const char **cpp;
83 
84     /* This is the URL for your mailserver */
85     curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");
86 
87     /* Note that this option isn't strictly required, omitting it will result
88      * in libcurl sending the MAIL FROM command with empty sender data. All
89      * autoresponses should have an empty reverse-path, and should be directed
90      * to the address in the reverse-path which triggered them. Otherwise,
91      * they could cause an endless loop. See RFC 5321 Section 4.5.5 for more
92      * details.
93      */
94     curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
95 
96     /* Add two recipients, in this particular case they correspond to the
97      * To: and Cc: addressees in the header, but they could be any kind of
98      * recipient. */
99     recipients = curl_slist_append(recipients, TO);
100     recipients = curl_slist_append(recipients, CC);
101     curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
102 
103     /* Build and set the message header list. */
104     for(cpp = headers_text; *cpp; cpp++)
105       headers = curl_slist_append(headers, *cpp);
106     curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
107 
108     /* Build the mime message. */
109     mime = curl_mime_init(curl);
110 
111     /* The inline part is an alternative proposing the html and the text
112        versions of the e-mail. */
113     alt = curl_mime_init(curl);
114 
115     /* HTML message. */
116     part = curl_mime_addpart(alt);
117     curl_mime_data(part, inline_html, CURL_ZERO_TERMINATED);
118     curl_mime_type(part, "text/html");
119 
120     /* Text message. */
121     part = curl_mime_addpart(alt);
122     curl_mime_data(part, inline_text, CURL_ZERO_TERMINATED);
123 
124     /* Create the inline part. */
125     part = curl_mime_addpart(mime);
126     curl_mime_subparts(part, alt);
127     curl_mime_type(part, "multipart/alternative");
128     slist = curl_slist_append(NULL, "Content-Disposition: inline");
129     curl_mime_headers(part, slist, 1);
130 
131     /* Add the current source program as an attachment. */
132     part = curl_mime_addpart(mime);
133     curl_mime_filedata(part, "smtp-mime.c");
134     curl_easy_setopt(curl, CURLOPT_MIMEPOST, mime);
135 
136     /* Send the message */
137     res = curl_easy_perform(curl);
138 
139     /* Check for errors */
140     if(res != CURLE_OK)
141       fprintf(stderr, "curl_easy_perform() failed: %s\n",
142               curl_easy_strerror(res));
143 
144     /* Free lists. */
145     curl_slist_free_all(recipients);
146     curl_slist_free_all(headers);
147 
148     /* curl won't send the QUIT command until you call cleanup, so you should
149      * be able to re-use this connection for additional messages (setting
150      * CURLOPT_MAIL_FROM and CURLOPT_MAIL_RCPT as required, and calling
151      * curl_easy_perform() again. It may not be a good idea to keep the
152      * connection open for a very long time though (more than a few minutes
153      * may result in the server timing out the connection), and you do want to
154      * clean up in the end.
155      */
156     curl_easy_cleanup(curl);
157 
158     /* Free multipart message. */
159     curl_mime_free(mime);
160   }
161 
162   return (int)res;
163 }
164