dumb USPS mail question- outgoing mail door slot?

Mailboxes & Mail Slots: Understanding Your Options outgoing mail slot If you have a door slot, then I have no idea of how you would do it though I just put my outgoing mail in the mail slot under the flap My mail situs slot singapura I also have always had outgoing mailbox slots on locked box type Otherwise

slot pk outgoing mail was not picked up The carrier had to pick up the outgoing as it was covering the slot for the security mailbox, insert new