about this subject I found the forum post: Email Notification for Submission Comments on 2013-14, and the Moodle Tracker MDL-58351" target="_blank" rel="noreferrer noopener">Email Notification for Submission Comments on 2013-19 for Moodle 3.2.2 & 3.4 and it seems there is no solution yet.
I have the same issue on Moodle 3.6 and I think it is important that students and teachers get a notification for the submission comments; otherwise they could miss useful or important information.
I already tried solving it (on Moodle 3.0) by adding a local help topic for Submission Comments, so students and teachers could know how to find them, anyway I think they skip that topic help so the submission comments too ;)
By now, my local-temporal solution is do not allow Submission Comments anymore –anyway it seems that most messages are actually missed—.
Does anyone here have a better solution for this?