Ran into the same issue.
There is a bug in CI_Email class::_write_headers().
This only happens, if
you are using the ‘mail’ protocol
AND are using the bcc_batch_mode
AND are sending the mail to more than the number of recipients defined in ‘bcc_batch_size’
=> this causes _write_headers() be called more than once and in the second round it tries to access the ‘Subject’ index it has unset in the first round.
To fix this, the following statement:
if ($this->protocol == 'mail')
{
$this->_subject = $this->_headers['Subject'];
unset($this->_headers['Subject']);
}
should be this:
if ($this->protocol == 'mail')
{
if (array_key_exists('Subject', $this->_headers))
{
$this->_subject = $this->_headers['Subject'];
unset($this->_headers['Subject']);
}
}
Here the complete fixed method (in system\libraries\Email.php)
/**
* Write Headers as a string
*
* @access private
* @return void
*/
function _write_headers()
{
if ($this->protocol == 'mail')
{
if (array_key_exists('Subject', $this->_headers))
{
$this->_subject = $this->_headers['Subject'];
unset($this->_headers['Subject']);
}
}
reset($this->_headers);
$this->_header_str = "";
foreach($this->_headers as $key => $val)
{
$val = trim($val);
if ($val != "")
{
$this->_header_str .= $key.": ".$val.$this->newline;
}
}
if ($this->_get_protocol() == 'mail')
{
$this->_header_str = rtrim($this->_header_str);
}
}
Any comments?
