We received the attached email from Apple, but the MDM mentioned in the email says "null." When I log into our JSS, there are no notifications to renew APNS? How can I tell if it needs to be renewed? 
Question
Strange APNS Renewal Email
+5
+13You should check the Apple APNS portal for any other APNS certs that may be set to expire. The account may have been used in the process of testing other MDMs. Unless there are any other notes you may need to do a more environmental search but this should give you a good start.
+24Settings > Global Management > Push Certificates in your Jamf Pro server should show you the actual expiration date of your APNs cert. I agree with @andrew.nicholas that this is most likely coming to you because somewhere along the line the same Apple ID was used to generate a test APNs cert for a beta or trial or something. I'm not sure why the email would be stating null for the MDM, but I would log in to Apple's APNs site and check out what's there.
+5Thank you. I checked the site and didn't see anything but apparently I was logged into the wrong account and didn't notice. Whoops.
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