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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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.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.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/* <DESC>
* Send email with SMTP
* </DESC>
*/
#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
/*
* For an SMTP example using the multi interface please see smtp-multi.c.
*/
/* The libcurl options want plain addresses, the viewable headers in the mail
* can get a full name as well.
*/
#define FROM_ADDR "<sender@example.org>"
#define TO_ADDR "<addressee@example.net>"
#define CC_ADDR "<info@example.org>"
#define FROM_MAIL "Sender Person " FROM_ADDR
#define TO_MAIL "A Receiver " TO_ADDR
#define CC_MAIL "John CC Smith " CC_ADDR
static const char *payload_text =
"Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n"
"To: " TO_MAIL "\r\n"
"From: " FROM_MAIL "\r\n"
"Cc: " CC_MAIL "\r\n"
"Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
"rfcpedant.example.org>\r\n"
"Subject: SMTP example message\r\n"
"\r\n" /* empty line to divide headers from body, see RFC 5322 */
"The body of the message starts here.\r\n"
"\r\n"
"It could be a lot of lines, could be MIME encoded, whatever.\r\n"
"Check RFC 5322.\r\n";
struct upload_status {
size_t bytes_read;
};
static size_t read_cb(char *ptr, size_t size, size_t nmemb, void *userp)
{
struct upload_status *upload_ctx = (struct upload_status *)userp;
const char *data;
size_t room = size * nmemb;
size_t len;
if((size == 0) || (nmemb == 0) || ((size * nmemb) < 1)) {
return 0;
}
data = &payload_text[upload_ctx->bytes_read];
len = strlen(data);
if(room < len)
len = room;
memcpy(ptr, data, len);
upload_ctx->bytes_read += len;
return len;
}
int main(void)
{
CURL *curl;
CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
if(result != CURLE_OK)
return (int)result;
curl = curl_easy_init();
if(curl) {
struct curl_slist *recipients = NULL;
struct upload_status upload_ctx = { 0 };
/* This is the URL for your mailserver */
curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");
/* Note that this option is not strictly required, omitting it results 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_ADDR);
/* 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_ADDR);
recipients = curl_slist_append(recipients, CC_ADDR);
curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
/* We are using a callback function to specify the payload (the headers
* and body of the message). You can use the CURLOPT_READDATA option to
* specify a FILE pointer to read from. */
curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_cb);
curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
/* Send the message */
result = curl_easy_perform(curl);
/* Check for errors */
if(result != CURLE_OK)
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(result));
/* Free the list of recipients */
curl_slist_free_all(recipients);
/* curl does not send the QUIT command until you call cleanup, so you
* should be able to reuse 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 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);
}
curl_global_cleanup();
return (int)result;
}
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