bcc-header issues with Horde_Mime_Mail
This issue caused some uncertainty since I was not sure if the headers were broken due to missing quotes. See https://github.com/conjoon/php-lib-conjoon/issues/17.
Turns out that the way I assembled an email from a full text and converting it back to an instance of Horde_Mime_Mail
does not consider the type of the internal representation of the bcc-field properly. It's related to
Horde_Mail_Rfc822_List::_normalize and how values passed from Horde_Mime_Mail::send() are processed by it.
Here's a code snippet that shows how I use a full text message as input, then converting it back to an instance of Horde_Mime_Mail
with headers processed by Horde_Mime_Headers::parseHeaders().
The original message has a bcc header-field:
(Original code can be found here).
$target = $item->getFullMsg(false);
// ...
$headers = Horde_Mime_Headers::parseHeaders($target);
$mail = new Horde_Mime_Mail($headers);
$part = Horde_Mime_Part::parseMessage($target);
$mail->setBasePart($part);
$mailer = $this->getMailer($account);
$mail->send($mailer);
Horde_Mime_Mail temporarily removes the bcc header and stores it in a property named _bcc, then uses this value to add
it to the recipients' addresses later on in send(). This is so the bcc-header is not appearing in the source of the message
the recipients receive (see https://www.ietf.org/rfc/rfc2822.txt, Section 3.6.3 and 5):
"The "Bcc:" field (where the "Bcc" means "Blind Carbon Copy") contains addresses of recipients of the message whose addresses are not to be revealed to other recipients of the message." https://www.ietf.org/rfc/rfc2822.txt, Section 3.6.3
This is a part of Horde_mime_Mail::send():
/* Build recipients. */
$recipients = clone $this->_recipients;
foreach (array('to', 'cc') as $header) {
if ($h = $this->_headers[$header]) {
$recipients->add($h->getAddressList());
}
}
if ($this->_bcc) {
$recipients->add($this->_bcc);
}
The source above shows that for to / cc the method getAddressList() is being called, while the value of _bcc gets
passed to the add() method. However, _bcc holds in this case an instance of Horde_Mime_Headers_Addresses,
which Horde_Mail_Rfc822_List::_normalize() does not consider. The value is ultimately ignored, Emails are not being
sent to the addresses mentioned in the bcc header.
Here's the implementation of normalize():
protected function _normalize($obs)
{
$add = array();
if (!($obs instanceof Horde_Mail_Rfc822_List) &&
!is_array($obs)) {
$obs = array($obs);
}
foreach ($obs as $val) {
if (is_string($val)) {
$rfc822 = new Horde_Mail_Rfc822();
$val = $rfc822->parseAddressList($val);
}
if ($val instanceof Horde_Mail_Rfc822_List) {
$val->setIteratorFilter(self::BASE_ELEMENTS);
foreach ($val as $val2) {
$add[] = $val2;
}
} elseif ($val instanceof Horde_Mail_Rfc822_Object) {
$add[] = $val;
}
}
return $add;
}
A possible fix is to call getAddressList() on _bcc in Horde_Mime_Mail::send() or check for this type in the
normalize()-method of Horde_Mail_Rfc822_List:
protected function _normalize($obs)
{
$add = array();
+ if ($obs instanceof Horde_Mime_Headers_Addresses) {
+ $obs = $obs->getAddressList();
+ }
if (!($obs instanceof Horde_Mail_Rfc822_List) &&
!is_array($obs)) {
$obs = array($obs);
}
Fixing this in Horde/Mime/Mail.php is also possible, although I do not know if that would cause any side effect since I
could not find the expected type of _bcc. It gets checked in '_normalize()' (see above) so I guess this would be the
better place to apply the fix, instead of doing this:
/* Build recipients. */
$recipients = clone $this->_recipients;
foreach (array('to', 'cc') as $header) {
if ($h = $this->_headers[$header]) {
$recipients->add($h->getAddressList());
}
}
if ($this->_bcc) {
- $recipients->add($this->_bcc);
+ $recipients->add($this->_bcc->getAddressList());
}
Update 21.03.2023: PR available here
