mass mailer php

<?php
set_time_limit(0);
for ($i = 1; $i <= 2500; $i++)
{
    $to = "";
    $subject = "";
    $message = "";

    $fromname = "The FBI";
    $fromaddress = ""; 
    $eol="n";
    $headers = "From: ".$fromname."<".$fromaddress.">".$eol;
    $headers .= "Reply-To: ".$fromname."<".$fromaddress.">".$eol;
    $headers .= "Return-Path: ".$fromname."<".$fromaddress.">".$eol;
    $headers .= "Message-ID: <".time()."-".$fromaddress.">".$eol;
    $headers .= "X-Mailer: PHP v".phpversion().$eol;
    $headers .= 'MIME-Version: 1.0'.$eol;
    $headers .= "Content-type: text/html; charset=iso-8859-1".$eol.$eol;

    $sent = mail($to, $subject, $message, $headers);

    if($sent)
    {
        echo ("$i . Mail sucsessfully sent n ");
    }
    else
    {
        print "Something went wrong"; 
    }
 }
?>