Historical clue formulations

• Org. that delivers — 2024-07-25
• Mail inits. since 1971 — 2024-02-20
• Delivery org. — 2023-11-05
• Org. with "Informed Delivery" emails — 2023-10-15
• Org. with a Click-N-Ship option — 2023-09-03
• "Neither rain nor snow …" org. — 2023-04-11
• Forever stamp letters — 2023-02-07
• Click-N-Ship org. — 2022-07-02
• Org. that delivers — 2021-05-09
• Mailing letters? — 2020-05-04
• "We deliver for you" sloganeer, for short — 2020-03-21
• Org. with a Change My Address portal on its website — 2019-05-10
• "We deliver for you" org. — 2018-10-04
• Org. that delivers — 2017-05-14
• Offerer of package deals, in brief — 2014-10-09
• Mail letters? — 2013-05-06
• Org. with stamps — 2013-03-18
• Mail letters — 2012-12-30
• Org. suggested by the starts of 17-, 31-, 41- and 62-Across — 2012-10-23
• Mail letters — 2011-07-11
• Inits. on a mail truck — 2011-04-12
• Census form deliverer: Abbr. — 2010-11-14
• Org. that trademarked "Pony Express" in 2006 — 2009-08-15
• Mail carrier's grp. — 2008-08-18
• Letter carriers' grp. — 2007-12-17
• Mail letters — 2006-10-29
• One way to send pkgs. — 2006-07-18
• "We deliver for you" sloganeer: Abbr. — 2005-12-13
• Deliverer of many pkgs. — 2005-03-13
• Letter carriers' org. — 2004-04-06
• Org. whose workers may be left carrying the bag — 2003-11-11
• Mail org. — 1999-08-17
• Its symbol is an eagle: Abbr. — 1999-03-14