BCC headers end up in TO field

Hello!
I have the Elastic Email sender plug-in and BBPress forum installed. When users subscribe to topics or replies, the system generates one e-mail message and puts all subscribers into the BCC header.

It looks like the Elastic Email plug-in is merging the BCC with the TO fields and therefore exposing all e-mail addresses to all users receiving the message.

This is unacceptable privacy-wise and I’m looking for a solution.
I believe the issue may be caused by lines 129-131 in ees_mail.php, within function “send”.

if (!is_array($to)) { $to = array_merge(explode(‘,’, $to), $bcc); }

Please advise!