Historical clue formulations

• Looped in via email — 2026-09-23
• On a chain, say — 2026-02-21
• Included in correspondence, in a way — 2025-09-10
• Kept up to speed, in a way — 2024-11-08
• Listed below a recipient, maybe — 2023-09-03
• Kept in the loop, in a way — 2022-12-14
• Included on an email, briefly — 2022-11-21
• Added to a thread, say — 2022-05-08
• Kept informed, in a way — 2022-02-17
• Looped in, in a way — 2021-07-23
• Included in an email, in brief — 2021-07-19
• Included, in a way — 2020-07-04
• Included in an email chain — 2019-09-11
• Looped in, in a way — 2018-04-22
• Looped in, in a way — 2017-01-21
• Included on an email — 2014-12-18
• Included via email — 2014-12-09
• E-mailed a dupe to — 2010-10-13
• Sent duplicates to, briefly — 2005-02-13
• Sent a duplicate, briefly — 2004-07-03
• Made an additional recipient, for short — 2002-02-17