Not getting new comment notices

About a week ago I suddenly stopped getting noticed in my email about new comments. I still get the ones notifying me about the comments held for moderation, but the legit comments that immediately post I am not.

I’ve also talked to my visitors and several have said that even though they are subscribed to comments’ new replies, they haven’t been getting the emails for the last week or so either.

Because I’m getting notice of the spam comments, I don’t think this is an issue with my host. I’ve double checked my settings and everything is correct- email address, sent email when new comment posted, send email when comment held for moderation. I’ve searched the forums here and apparently this was an issue for some uses about 4 or 5 years ago, but nothing recently and no one seemed to have a fix for it then either.

Any suggestions as to what may be causing this glitch? Thanks.