Return Passport Registered Post

I have a question for anybody how has receive the passport recently.

I was wonder if when you received the acknowledge letter and the passport and there is nobody at home, do they just put the letter in the mailbox? Or somebody needs to be home to receive the package?

Given the Covid-19 I think you do not need to sign but I somebody needs to be there. I was wondering if they ring the bell or just slip the letter in the box.

I just received my passport and acknowledge letter, it was sent by express mail which requires somebody to be at home