The wilful interception or destruction of mail without the consent of the sender or the recipient is a federal offense. If you suspect that a current or former landlord is throwing away your mail, opened or unopened, report it to the relevant authorities. The penalties for tampering with U.S. mail are a prison sentence of up to five years, a fine of up to $250,000 or both.
Locate the contact details of the postmaster at your nearest post office using the United State Postal Service postmaster (usps.com/postmasterfinder) finder as soon as you become aware of your mail going missing.
Report the suspected interception of your mail to the postmaster at you nearest post office. Provide as much detail about the mail that has gone missing and the people that could have had access to it as you can.
File a complaint with the U.S. Postal Inspection Service if you believe your landlord is victimizing you by intercepting and disposing of your mail.