send email without using libcurl.dll in c++ - c++

Question

I written a simple little code based around libcurl that sends a email to myself:
#include <cstdio>
#include <cstring>
#include <curl/curl.h>
static const char* payload_text[] = {
"To: " "<myemail#web.de>" "\r\n",
"From: " "<myemail#web.de>" " (Example User)\r\n",
"Cc: " "<myemail#web.de>" " (Another example User)\r\n",
"Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd#"
"rfcpedant.example.org>\r\n",
"Subject: Hello\r\n",
"\r\n",
"The body of the message starts here.\r\n",
"\r\n",
"Test.\r\n",
nullptr
};
struct upload_status {
int lines_read;
};
static size_t payload_source(void* ptr, const size_t size, const size_t nmemb, void* userp)
{
auto* const upload_ctx = static_cast<struct upload_status*>(userp);
if (size == 0 || nmemb == 0 || size * nmemb < 1) {
return 0;
}
const auto* const data = payload_text[upload_ctx->lines_read];
if (data) {
const auto len = strlen(data);
memcpy(ptr, data, len);
upload_ctx->lines_read++;
return len;
}
return 0;
}
int _stdcall WinMain(struct HINSTANCE__* hinstance, struct HINSTANCE__* hprevinstance, char* cmdline, int cmdshow)
{
auto res = CURLE_OK;
struct curl_slist* recipients = nullptr;
struct upload_status upload_ctx;
upload_ctx.lines_read = 0;
auto* const curl = curl_easy_init();
if (curl) {
curl_easy_setopt(curl, CURLOPT_USERNAME, "myemail#web.de");
curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
curl_easy_setopt(curl, CURLOPT_URL, "smtp://smtp.web.de:587");
curl_easy_setopt(curl, CURLOPT_USE_SSL, static_cast<long>(CURLUSESSL_ALL));
curl_easy_setopt(curl, CURLOPT_MAIL_FROM, "<myemail#web.de>");
recipients = curl_slist_append(recipients, "<myemail#web.de>");
recipients = curl_slist_append(recipients, "<myemail#web.de>");
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 static_cast<int>(res);
}
NOTE: thats not my password there in curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
The above code works. but i needs libcurl.dll and zlib1.dll
I would like it in a single .exe file
My question is.. Is that possible in c++, i know its possible in c# with using System.Net.Mail or something, or is there are alternative to my code that doesn't require external .dlls