If the /State of Maine/ sent that to him at his out-of-state address, it is a federal felony and direct evidence of fraud by the Maine officials.
Your local FBI office should be made aware of this illegal activity.
PDF/scan a letter with the evidence, send it locally and CC AG Barr at DOJ and your “lawyer” (I recommend Jay Sekulow at the ACLJ).
It was not from “the state.” He turned over the information to the Maine Sec of State. I recalled seeing a website here on the FreeQ thread to report to feds and I used that site. (Reporting all info on the mailer)
Sidenote: still have 3 kids plus their spouses in ME. I have given instructions in my tagline regarding Susan Collins and SCOTUS vote. 6 voters calling can’t hurt.