People who steal mail are usually looking for envelopes containing personal checks that are made out to pay bills. They wash the check with chemicals to remove the payee’s name and amount. The result is a blank check signed by you. They can then fill in their names and an amount and cash it. You can prevent your checks from being stolen by depositing your mail in boxes or slots inside a post office. Or use an outside box only if there is another pickup that day. It is not safe to leave mail in a box overnight. Never leave mail for pickups from personal curbside boxes or cluster box units. And when making out checks use a pen with ink that is resistant to washing.