I received a check today also. Payable to my mother with the word “DECD” and next line “%” my name. It also has a check box saying if the recipient deceased check the box and drop in mailbox. My mother passed away in 2018 and I filed her final return in 2019. I am the estate administrator of her account that has a federal tax ID and is still active. Do I drop it off at mailbox ASAP?