I cannot send an email using curl and c++ - c++

Question

im trying to send an email with curl and c++ just like this example but when i execute the program:
#include <iostream>
#include <curl/curl.h>
int main()
{
int a;
char errbuf[CURL_ERROR_SIZE] = {0};
CURL *curl = curl_easy_init();
CURLcode res;
struct upload_status upload_ctx = { 0 };
if(curl)
{
curl_easy_setopt(curl, CURLOPT_URL, "smtps://smtp.gmail.com:465");
curl_easy_setopt(curl, CURLOPT_MAIL_FROM, "");
curl_easy_setopt(curl, CURLOPT_PASSWORD, "");
curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, "");
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_CAINFO, "D:\\MinGW\\cacert.pem");
curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, errbuf);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
check_errors(res, errbuf);
return 0;
}
i get this error:
curl_easy_perform() failed: Failed sending data to the peer
libcurl: (55) MAIL failed: 530
I deleted most of the code because i couldn't post the question but the rest is in the example.

Answer 1

The problem i had in my code was that i thought that by using:
curl_easy_setopt(curl, CURLOPT_MAIL_FROM, "myemail#example.com"); i was specifyng the username, which was in fact, an error.
To specify the username libcurl has another option:
curl_easy_setopt(curl, CURLOPT_USERNAME, "myemail#example.com");