Under most normal circumstances, I will normally send and receive mail on Mondays, and Thursdays. With letters that have a domestic postmark, it would show as sent on those respective days. I usually collect my mail in the morning, and reply to the letters when I return home. And as mentioned, the letter will be postmarked for the next Monday, or Thursday. For the rarity of an instance that someone sent a letter to my PO Box, I will collect that on Thursday, and as with above, letter will be postmarked for Monday, and the return address will show my mailing address instead of my PO Box.