This error occurs when i try to use a sign up feature and im not sure as to why it is giving me this error. I have been to the page it is quoting and am still unsure as how i can correct the code that im using.. im on a go daddy hosting server if that help or is part of the error thanks :D
Warning: mail() [function.mail]: SMTP server response: 451 See http://pobox.com/~djb/docs/smtplf.html. in D:\Hosting\12090176\html\flashrevise\signup.php on line 101
$u = preg_replace('#[^a-z0-9]#i', '', $_POST['u']);
$e = mysqli_real_escape_string($db_conx, $_POST['e']);
$p = $_POST['p'];
$g = preg_replace('#[^a-z]#', '', $_POST['g']);
$c = preg_replace('#[^a-z ]#i', '', $_POST['c']);
$to = "$e";
$from = "auto_responder@flashrevise.co.uk";
$subject = 'Flash Revise Account Activation';
$message = '<!DOCTYPE html><html><head><meta charset="UTF-8"><title>Flash Revise Message</title></head><body style="margin:0px;
font-family:Tahoma, Geneva, sans-serif;"><div style="padding:15px; background:#333; font-size:24px; color:#CCC;"><a href="http://www.flashrevise.co.uk">
<img src="http://localhost:8101/Tutorials/sandbox/myfiles/FlashRevise/style/images/logo_white.png" width="36" height="30" at="Flash Revise" style="boder:none; float:left;"></a>
Flash Revise Account Activation </div><div style="padding:24px" font-size:17px;"> Hello '.$u.',<br><br> Click the link below to activate your account<br><br>
<a href="http://localhost:8101/Tutorials/sandbox/myfiles/FlashRevise/activation.php?id='.$uid.'&u='.$u.'&e='.$e.'&p='.$p_hash.'"> Click here to activate your account now</a><br>
<br> Login after successful activation using: <br>* Email Address:<b> '.$e.'</b><br>* Password: <b> '.$p.'</b></div></body></html>';
$headers = "From: $from
";
$headers .= "MIME-VERSION 1.0
";
$headers .= "Content-type: text/html; charset=iso-8859-1
";
mail($to, $subject, $message, $headers);
