how to send an email using libcurl - c++

Question

I'm able to send an email to my gmail successfully, but it's sending an empty message and not able to send contain message , anyway the code I'm using is as follows:
#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
#define FROM "<xxxxxx#gmail.com>"
#define TO "<xxxxx#gmail.com>"
static const char* payload_text[] =
{
"To: " TO "\r\n",
"From: " FROM "\r\n",
"Subject: SMTP TLS example message\r\n",
"Contain: Helllo\r\n",
NULL
};
struct upload_status {
int lines_read;
};
static size_t payload_source(void* 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) {
curl_easy_setopt(curl, CURLOPT_USERNAME, "xxxxxx#gmail.com");
curl_easy_setopt(curl, CURLOPT_PASSWORD, "xxxxxxxx");
curl_easy_setopt(curl, CURLOPT_URL, "smtp://smtp.gmail.com:587");
curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL);
curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
recipients = curl_slist_append(recipients, TO);
curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
res = curl_easy_perform(curl);
if (res != CURLE_OK)
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(res));
curl_slist_free_all(recipients);
curl_easy_cleanup(curl);
}
return (int)res;
}
How to fix this ? I have no acquaintance with this library,and the only thing I can receive is the subject, Thanks if anyone can help

Answer 1

static const char* payload_text[] =
{
"To: " TO "\r\n",
"From: " FROM "\r\n",
"Subject: SMTP TLS example message\r\n",
"Contain: Helllo\r\n",
NULL
};
should be something like
static const char* payload_text[] =
{
"To: " TO "\r\n",
"From: " FROM "\r\n",
"Subject: SMTP TLS example message\r\n",
"\r\n",
"Helllo\r\n",
NULL
};
That is Contain: is wrong, and there should be a blank line between the headers and the message.
Email format is described here.