PHP mail special characters in subject field

Question

I would like to insert special characters in the subject of HTML e-mails sent with the PHP mail() function.

I want my subject to look like this:

★ Your new account

I have tried with an HTML entity like ★ (★) or by pasting the symbol directly in my code but that doesn't work either, except on a few e-mail clients.

$to = 'me@example.com';
$subject = '★ Your new account or ★ Your new account';
$message = 'HTML message...';

$headers = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'Content-type: text/html; charset=utf-8' . "\r\n";
$headers .= 'From: Me <me@example.com>' . "\r\n";

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

Any advice on how to get this to work properly? Thank you.

Answer 1

Try for subject:

$sub = '=?UTF-8?B?'.base64_encode($subject).'?=';

And then:

mail($to, $sub, $message, $headers);

Answer 2

While the accepted answer works fine, it makes it impossible to read the subject when looking at the raw headers. Here's an alternative that keeps the line readable and also shorter if it consists of mostly ascii characters.

$subject = '=?UTF-8?q?' . quoted_printable_encode($subject) . '?=';

Here's the encoded subject line of the accepted answer:

=?UTF-8?B?4piFIFlvdXIgbmV3IGFjY291bnQ=?=

Here's the encoded subject line of my answer:

=?UTF-8?q?=E2=98=85 Your new account?=

Answer 3

 $headers="";    
 $message = utf8_encode($message);
 $message = wordwrap($message, 70, "\r\n");
 $subject = '=?UTF-8?B?'.base64_encode(utf8_encode($subject)).'?=';
 $to_name = '=?UTF-8?B?'.base64_encode(utf8_encode($to_name)).'?=';
 $from_name = '=?UTF-8?B?'.base64_encode(utf8_encode($from_name)).'?=';

 $headers .= "MIME-Version: 1.0" . "\r\n"; 
 $headers .= "Content-type: text/plain; charset=utf-8" . "\r\n"; 
 //$headers .= "Content-Transfer-Encoding: quoted-printable" . "\r\n"; 
 $headers .= "From: $from_name <$from_email>" . "\r\n"; 
 $headers .= "To: $to_name <$to_email>" . "\r\n";
 $headers .= "Subject: $subject" . "\r\n";
 $headers .= "X-Mailer: PHP/" . phpversion();  

 mail("", $subject, $message, $headers);