(This measure has not been amended since it was reported to the Senate on October 16, 2017. The summary of that version is repeated here.) Strengthening the Department of Homeland Security Secure Mail Initiative Act (Sec. 3) This bill directs the Department of Homeland Security (DHS) to provide for an option under which a person to whom a document is sent under the Secure Mail Initiative may elect to have the U.S. Postal Service (USPS) use the Hold for Pickup service or the Signature Confirmation service in delivering the document. DHS shall require payment of a fee for such services, which shall be deposited into the Immigration Examinations Fee Account and used to cover DHS and USPS costs of providing such services. The USPS: (1) may promulgate regulations that minimize such costs and do not require it to incur additional expenses that are not recoverable, and (2) shall notify DHS of any changes to such services. If DHS determines that substantially similar services offered by a private carrier would provide better service and value than the USPS services, it may discontinue use of the USPS services and enter into a contract with the private carrier. (Sec. 4) DHS must report to Congress within two years of this bill's enactment describing the implementation of requirements under this bill, the fee imposed, and the number of times during the previous year that a person used a service under this bill.