JotForm submission restriction for certain IP addresses?

We have certain users who are submitting forms regularly, but the forms are not generating emails after submission. This has been happening since about 10 a.m. Central.

We can see the successful submission when Viewing Submissions within Jotform, but there is no record of an email being sent to the correct address. Oddly, the email address that is listed works fine for other user submissions. Only certain users (IP address, possibly) appear to be blocked, possibly?

Example: Submission ID 3958296903679593891 has not generated an email to the address

Update -- Jotform does record that an email is sent to leedesigncenter1+guyq7rjp4pobbb4fajnb@boards.trello.com, but this is not received on the other end (#71166385978169). Conversely, an email sent one minute earlier to the same email address but from a different form (#71094083478159) was received without issue.

We apologize for any inconvenience caused. We had delayed email delivery issues early today. But the backend team had restored the service already back to normal as of this time.

Can you please check and test again. Let us know if you are still having delayed emails from your form submissions.

Thanks.