The Secretary shall disapprove a firearm application if: the Secretary determines that the firearm applicant supplied false information or made a false statement; the Secretary determines that the firearm application is not properly completed; or the Secretary receives written notification from the firearm applicant’s licensed attending physician that the firearm applicant suffers from a mental disorder and is a danger to the firearm applicant or to another. If the Secretary disapproves a firearm application, the Secretary shall notify the prospective seller, lessor, or transferor in writing of the disapproval within 7 days after the date that the executed firearm application is forwarded to the Secretary by certified mail or facsimile machine. After notifying the prospective seller, lessor, or transferor under paragraph (1) of this subsection, the Secretary shall notify the prospective purchaser, lessee, or transferee in writing of the disapproval. The date when the prospective seller, lessor, or transferor forwards the executed firearm application to the Secretary by certified mail or by facsimile machine is the first day of the 7-day period allowed for notice of disapproval to the prospective seller, lessor, or transferor.