/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2020, 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. * ***************************************************************************/ /* <DESC> * Send e-mail 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 very well 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 RFC5322 */ "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 RFC5322.\r\n", NULL }; struct upload_status { int lines_read; }; static size_t payload_source(char *ptr, size_t size, size_t nmemb, void *userp) { struct upload_status *upload_ctx = (struct upload_status *)userp; const char *data; if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) { return 0; } data = payload_text[upload_ctx->lines_read]; if(data) { size_t len = strlen(data); memcpy(ptr, data, len); upload_ctx->lines_read++; return len; } return 0; } int main(void) { CURL *curl; CURLcode res = CURLE_OK; struct curl_slist *recipients = NULL; struct upload_status upload_ctx; upload_ctx.lines_read = 0; 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_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're using a callback function to specify the payload (the headers and * body of the message). You could just use the CURLOPT_READDATA option to * specify a FILE pointer to read from. */ curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source); curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx); curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L); /* 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 the list of recipients */ curl_slist_free_all(recipients); /* 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); } return (int)res; }