Description:
------------
I'm trying to send an email with Bcc recipients, they get a copy, but the Bcc header isn't stripped out.

I already tested using different character cases, like Bcc, BCC, bcc. And already tested using \n and \r\n as headers glue.

Reproduce code:
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<?php

  mail('from@goobar.com', 'subject', 'message', 'Bcc: email@foobar.com');

?>

Expected result:
----------------
from@goobar.com and email@foobar.com receive the same message, but without one know the other.

Actual result:
--------------
from@goobar.com is receiving the following message:

Subject: subject
Bcc: email@foobar.com

message