mailer.php

<?php

// https://habr.com/ru/post/26518/

$from = "from@mail.com";

ini_set("sendmail_from", $from);
ini_set("SMTP", "myserver");
ini_set("smtp_port", 25);

$to = "serabass565@gmail.com";
$subject = "Email Subject";

$message = "Dear " . "name" . ",<br>";
$message .= "We welcome you to be part of family<br><br>";
$message .= "Regards,<br>";

// Always set content-type when sending HTML email
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=UTF-8" . "\r\n";

// More headers
$headers .= "From: <" . $from . ">" . "\r\n";
$headers .= "Cc: myboss@example.com" . "\r\n";

mail($to, $subject, $message, $headers);
?>