The filter can be used to allow to send the mail to the subscriber or not.
Changelog
since 7.0.0 version
Parameters
1. $sendMail (type: bool) – if the mail should be sent or not
2. $emailData (type: array) – subscription data
3. $comment (type: WP_Comment object) – the object of the comment
Usage
add_filter("wpdiscuz_email_notification", function ($sendMail, $emailData, $comment) {
return false;
}, 10, 3);