外部メールサーバーからメール送信するPHPの関数（簡略版）

<?php
    require_once "Mail.php";
    $mail_info = ["host" => "ホスト名", "port" => 587, "auth" => true, "username" => "メールアカウント名", "password" => "パスワード", "timeout" => 20];
    $mail_from_address = "デフォルトの送信元メアド";
    function send($to_mail, $subject, $body, $from_mail = "", $charset = "ISO-2022-JP"){
        $obj = &Mail::factory("smtp", $GLOBALS["mail_info"]);
        $ret = $obj->send([$to_mail], ["From" => mb_encode_mimeheader(($from_mail == "" ? $GLOBALS["mail_from_address"] : $from_mail), $charset), "To" => $to_mail, "Cc" => "", "Bcc" => "", "Subject" => mb_encode_mimeheader($subject, $charset), "Content-Type" => "text/plain; charset=".$charset], mb_convert_encoding($body, $charset, "UTF-8"));
        return PEAR::isError($ret) ? false : true;
    }
    // 送信テスト
    // send("送信先メアド", "テスト件名", "テスト内容");
?>