This memo from the Office of Legal Counsel was released January 17, 2024, but was written February 27, 2020 (i.e., late in the first Trump administration and well before Election Day). There is an editor’s note that the Electoral Count Reform Act eliminated references to “registered mail.” But despite the fact that much of the memo has been superseded by statute, the framing of the memo presents interesting observations about the role of the Archivist in relation to certificates of electors’ votes:

We conclude that federal law does require state officials to send their electoral certificates by USPS’s registered-mail service. The plain language of the statute requires the use of registered mail, and this interpretation is supported by the history of the statute, Congress’s decision to amend other statutory provisions, and the relevant judicial precedent. But the statute places no restrictions on the Archivist’s acceptance of the States’ certificates. Instead, it calls for him to request duplicate copies only if he does not “receive[]” a State’s vote certificates. 3 U.S.C. §§ 12, 13. The statute therefore does not require the Archivist to reject certificates sent by an unauthorized means. By refusing receipt, the Archivist would thwart the statutory scheme, which seeks to ensure that the States reliably transmit the certificates to the Archivist for the purpose of keeping the official records and, in the case of the certificates of the electors’ votes, as duplicates of the vote certificates sent to the President of the Senate.