Historical clue formulations

• Ships, say — 2026-09-24
• Slips in a slot at the post office — 2026-09-07
• Sends off — 2025-08-24
• Extorts from, in a way — 2024-07-28
• Sends, as a postcard — 2023-12-11
• Puts in a box, perhaps — 2019-11-16
• Posts — 2015-06-18
• Posts — 2000-03-29
• Drops in the letter box — 1998-12-08
• Posts — 1998-02-13