iCloud Mail (web) — "This message could not be loaded at this time. Try again later." — persistent error on specific message(s)

I'm getting the error "This message could not be loaded at this time. Try again later." when trying to open a specific message in iCloud Mail via the web interface (icloud.com/mail).

Details:

Affected message: a Fail2Ban "recidive" notification email (automated server alert), plain text format Behavior: the error appears consistently, every time I try to open this message — it is not a one-off glitch Browser: [ANY like Mozilla Firefox, Chromium based] Device: [ANY like Linux, Windows or macOS computers] Other messages in the inbox load normally — this appears isolated to specific message(s) like Fail2Ban or some any others too I have not made any recent account/security changes (no forwarding rules, no new filters)

Troubleshooting already tried:

Reloading / trying again after a delay — no change Unchecked "Block All Remote Content" setting under Privacy & Security Message loads fine on iPhone Mail app or any other Mail Client apps on PC but fails on iCloud.com

Question: Is this a known/reported server-side issue with iCloud Mail (possibly related to malformed IMAP ENVELOPE responses for certain automated/plain-text messages)? Are there any workarounds besides waiting for a server-side fix, or is there a way to force a resync of a specific message?

Any guidance would be appreciated — this message is time-sensitive (a security-related server alert), so I'd like to access its content as soon as possible.

iCloud Mail (web) — "This message could not be loaded at this time. Try again later." — persistent error on specific message(s)
 
 
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