<?php

$email  = trim($_GET["email"]);
$project_name = trim($_POST["project_name"]);

$letter = "Поздравляем, отправка сообщений на почту работает";
$from = "Learn French";
$subject = "French Tutors & Exams";
function adopt($text) {
    return '=?UTF-8?B?'.Base64_encode($text).'?=';
}

$headers = "MIME-Version: 1.0" . PHP_EOL .
"Content-Type: text/html; charset=utf-8" . PHP_EOL .
'From: '.adopt($project_name).'<nikita@hopesh.ru>' . PHP_EOL .
'Reply-To: nikita@hopesh.ru' . PHP_EOL;
mail($email, $subject, $letter, $headers);