PHP not sendig HTML template to email

Question

my problem is that when you register a user is generated random code that is sent to the email I made a template for emails that contains basic text together with styles this email only changes the basic link with the generated code.So everything should work as I meant but currently during registration comes email but without the styles that I gave. Codes below.

$to = $email;
$subject = "Registration Confirmation";

$link = "<a href='".DIR."/activation?x=$latest_id&y=$activasion'>".DIR."/activation?x=$latest_id&y=$activasion</a>";

$headers = "MIME-Version: 1.0" . "\r"; 
$headers .= "Content-Type: text/html; charset=iso-8859-1\r\n";

$headers .= 'From: '.$from."\r\n".
            'Reply-To: '.$from."\r\n" .
            'X-Mailer: PHP/' . phpversion();

$message = file_get_contents("inc/user_register.html");
$message = str_replace('[link]', $link, $message);

mail($to, $subject, $message, $headers);
header("location: /login?action=joined");

Answer 1

You are missing \n at the first headers[]. You can also try this way for setting the header.

// To send HTML mail, the Content-type header must be set
$headers[] = 'MIME-Version: 1.0';
$headers[] = 'Content-type: text/html; charset=iso-8859-1';

// Additional headers
$headers[] = 'To: Mary <mary@example.com>, Kelly <kelly@example.com>';
$headers[] = 'From: Birthday Reminder <birthday@example.com>';
$headers[] = 'Cc: birthdayarchive@example.com';
$headers[] = 'Bcc: birthdaycheck@example.com';

// Mail it
mail($to, $subject, $message, implode("\r\n", $headers));

Answer 2

PROBLEM SOLVED

I were using import font from google font website. I have deleted it from the styles and working like I wanted.