Not all submissions being emailed?

Within the past couple of days, not all of the submissions are being emailed to the email on file. It seems to be sporadic - one will come through, it will miss one, and then another will come through. Any thoughts on what might be happening?

Everything looks good with your account. We had a temporary slowdown in the last days. But it works fine now and you should be able to receive all notifications. If you have some missing notifications from today, please let us know.