I emailed today and here is their response.
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We are unable to locate your request at this time.
The current processing time for an FBI Background Check is taking 14-16 weeks to complete from the date the request was received. It can take 14+ weeks for a request to clear our security process, so we are not able to see the request in our system until then.
At this time we are opening mail we received on approximately 09/13/2017. We are unable to verify the delivery of a package until it is opened. If you submitted your request by courier (Fed Ex, UPS, or USPS), please view their web site to verify delivery.
Unfortunately, no requests can be expedited at this time due to the amount of work. All responses are mailed through the US Postal Service First Class Mail please allow standard mailing time (three weeks in the US and four weeks outside the US) to receive the response. There is no tracking number with the US Postal Service First Class Mail. Responses cannot be emailed.
When checking again for a status update, please be sure to supply your full name and date of birth.
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Looks like they cannot tell the status of your application or delivery confirmation etc until they actually open your envelope. So i guess their response is good only for getting the current date....