ZF-7291: Zend_Mail uses doublequotes in header charset which troubles several email clients
As already reported in issue ZF-6219, the character set in the Content-type header of MIME message part should not be quoted.
Content-Type: text/html; charset="utf-8"
The solution that was proposed there was to remove the quotes in Zend/Mime/Part.php which was done in the next release i think. The problem now is that the mentioned file is not the only one that quotes the mail headers that way. Another file that always set my headers wrong when I was setting an attachment:
Mail/Transport/Abstract.php (line 143):
$this->_headers['Content-Type'] = array( $type . '; charset="' . $this->_mail->getCharset() . '";' . $this->EOL . " " . 'boundary="' . $boundary . '"' );
Removing the doublequotes on the charset= part lets even outlook 2003 read my attachment properly =).