Pear PHP Mail sending CC doesn't seem to work - php

Question

I'm using PEAR's mail library via SMTP on my server and whilst I can get emails to generate, adding CC's doesn't seem to work. Basically the CC recipients never get their email even though the main recipient of the same email does.
My basic setup is as follows, all the recipient variables ($to,$cc,$bcc) are string variables containing either a single recipient email addresses or comma separated email addresses.
$headers = array (
'From' => $from,
'To' => $to,
'Cc' => $cc,
'Bcc' => $bcc,
'Subject' => $subject,
'Reply-To' => $from,
'X-Mailer' => 'PHP/' . phpversion(),
'MIME-Version' => '1.0',
'Content-Type' => 'text/html; charset=ISO-8859-1'
);
$smtp = Mail::factory('smtp', array (
'host' => $host,
'port' => $port,
'auth' => true,
'username' => $username,
'password' => $password
));
$result = $smtp->send($to, $headers, $message);
I've read that sending BCCs is more complex, so lets stick to the CCs... why aren't they being received ? Is there anything obvious that I'm doing wrong here ?

Answer 1

In order to send an email to CC or BCC with SMTP, you must list all email addresses both under recipients to the send() function and in the CC key within the header.
$to = "john#example.com";
$cc = "doe#example.com";
$recipients = $to . ", " . $cc;
$headers["From"] = "john#example.com";
$headers["To"] = $to;
$headers["Subject"] = "Hello World!";
$headers["Cc"] = "doe#example.com";
$headers["Reply-To"] = "john#example.com";
$send = $mail->send($recipients, $headers, $body);