WordPress, application emails end up in spam folder?

Question

Email

Hello, such a problem. Website on WordPress , hosting and site domain are on REG.RU , Cyrillic domain. Applications from the feedback form come, but for some reason they end up in the Spam folder.
I tried sending requests to Mail.ru and Google mail , in both cases they fell into spam. The PHP handler used my own, placed it in the root of the WordPress installation, the code is provided below. I also tried to send through the Contact Form 7 plugin , there, too, letters go to spam.
I don't know what to do anymore, can you please tell me how to solve this problem?

<?php
header("Content-Type: text/html; charset=utf-8");
$name = htmlspecialchars($_POST["name"]);
$tel = htmlspecialchars($_POST["phone"]);
$email = htmlspecialchars($_POST["email"]);
$refferer = getenv('HTTP_REFERER');
$date = date("d.m.y"); // число.месяц.год
$time = date("H:i"); // часы:минуты:секунды
$myemail = "[email protected]";
$tema = "Новый заказ";
$message_to_myemail = "Уважаемый администратор, Вам поступил новый заказ
<br><br>
Имя: $name<br>
Телефон: $tel<br>
Источник (ссылка): $refferer<br>
";


mail( $myemail, $tema, $message_to_myemail, "Reply-To: Davydov-Event \r\n"."MIME-Version: 1.0\r\n"."Content-type: text/html; charset=utf-8\r\n" );


$tema = "Заказ принят";
$message_to_myemail = "
Спасибо, Ваш заказ успешно принят
";
$myemail = $email;
mail($myemail, $tema, $message_to_myemail, "From: Davydov-Event \r\n Reply-To: WAYUP \r\n"."MIME-Version: 1.0\r\n"."Content-type: text/html; charset=utf-8\r\n" );

Answer 1

Yes, they said about smtp above and it's true. Or connect specialized services.
Take a look at the WP Mail SMTP plugin .

Answer 2

send via smtp