#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
 
#define GMAIL_USERNAME "your_email@gmail.com"
#define GMAIL_PASSWORD "your_password"
 
#define SMTP_SERVER "smtps://smtp.gmail.com"
#define SMTP_PORT 465
 
#define EMAIL_FROM GMAIL_USERNAME
#define EMAIL_TO "recipient@example.com"
#define EMAIL_SUBJECT "Hello"
#define EMAIL_BODY "Hi there,\n\nThis is an automated email."
 
int main() {
    CURL *curl;
    CURLcode res = CURLE_OK;
 
    curl = curl_easy_init();
    if (curl) {
        curl_easy_setopt(curl, CURLOPT_USERNAME, GMAIL_USERNAME);
        curl_easy_setopt(curl, CURLOPT_PASSWORD, GMAIL_PASSWORD);
        curl_easy_setopt(curl, CURLOPT_URL, SMTP_SERVER);
        curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_ALL);
        curl_easy_setopt(curl, CURLOPT_MAIL_FROM, EMAIL_FROM);
 
        struct curl_slist *recipients = NULL;
        recipients = curl_slist_append(recipients, EMAIL_TO);
        curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
 
        curl_easy_setopt(curl, CURLOPT_READFUNCTION, NULL);
        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
 
        struct curl_slist *headers = NULL;
        headers = curl_slist_append(headers, "Content-Type: text/plain; charset=\"UTF-8\"");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
 
        curl_easy_setopt(curl, CURLOPT_READDATA, NULL);
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, EMAIL_BODY);
        curl_easy_setopt(curl, CURLOPT_INFILESIZE, (long)strlen(EMAIL_BODY));
 
        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_slist_free_all(headers);
        curl_easy_cleanup(curl);
    } else {
        fprintf(stderr, "Failed to initialize libcurl\n");
        return 1;
    }
 
    return 0;
}
 

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