- mb_send_mail: documentation ( source)
<?php
$address = 'aaa@example.com';
$subject = 'タイトル';
$message = '本文';
$header = "Content-Transfer-Encoding: Base64\r\nContent-Type: text/plain; charset=UTF-8\r\nFrom: smile@smile-fjyuu-vagrant\r\nMime-Version: 1.0\r\n";
mb_send_mail($address , $subject , $message , $header);