mail ($_POST['email'], 'Thank you for registering with the list', $body, 'From: [email]paulr@summitmedia.co.uk[/email]', 'Cc: [email]paulr@summitmedia.co.uk[/email]');
Check out the manual. The mail function requires 3 parameters, and accepts a further two optional ones.
In your code above, they map out as
To: $_POST['email']
Subject: 'Thank you for registering with the list'
Message: $body
Additional Headers: 'From: paulr@summitmedia.co.uk'
Additional Parameters: 'Cc: paulr@summitmedia.co.uk'
Your cc above is not a valid parameter:
You might want to try:
$headers = "To: ". $_POST['email']. "\r\n";
$headers .= "From: List Manager <paulr@summitmedia.co.uk>" . "\r\n";
$headers .= "Bcc: paulr@summitmedia.co.uk" . "\r\n";
mail ($_POST['email'], 'Thank you for registering with the list', $body, $headers);
This sets the from and to, as well as setting a BCC value as well.