Yes, it is illegal to throw away someone else’s mail, a federal crime to be specific. If you’ve been finding your mail in the trash in your mailroom, there are a few steps you can take to stop your neighbors from messing with your mail.
Your first step is to talk to your landlord or building manager. If you let management know about your recent mail issues, they may be able to talk to your neighbors for you and sort it out. If it keeps happening after a warning, you can ask your landlord about installing cameras in the mailroom to get evidence of the mail tampering.
Your last resort is to report your neighbors for mail theft, especially if your mail starts to go missing instead of appearing in the trash. You can report mail theft through the USPS website or call 1-877-876-2455.